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Post by Stu on Jan 30, 2015 16:17:38 GMT
I have recently aquired an automatic engine which I've been fighting the urge to dismantle. I'm very keen to learn how these great auto boxes work and after some reading it appears they are quite complex and require several special tools to service them. Well I've got neither special tools or the experience to work on them, but I think I'll go as far as I can with it in the hope I dont break anything, or get to the point where I cant remember how to put it back together (its happened before) Anyway, I started by stripping off the easy stuff, cylinder head etc... I then gave it some beans on my lever bar to remove the torque convetor centre bolt (it gave up eventually). Then removed three bolts from the torque coverter to allow fitment of the extractor. The extractor is a modified clutch extractor for a manual. I extended the bolt holes to line up with the convertor bolt holes. I did'nt know whether it would work ok but to my relief it popped it off nicely. I then removed the low pressure valve, bell crank assembly and the converter housing bolts & nuts ready to take off the housing. I now need to figure out how to hold the converter output gear so I can remove the input gear nut. I realised this nut has to be removed before I can take off the converter housing . I think I may need to use an adapted manual clutch ring, although the tooth count is not the same so I know I wont be able to just pop a clutch disc hub on. It'll need to be cut and adapted as I've seen on the Austin America guys web site. I dont really want to sacrafice a clutch hub, so if anyone reading knows an easier way please let me know (I could well be missing something obvious) Thats all for now, and I'll post up some more when I get the housing off.
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Post by Stu on Feb 3, 2015 22:57:27 GMT
After a bit of thought and a lack of anything else to use, I decided I'd have to use a manual clutch plate after all. I knew the splines were different as the backplate has less teeth than the output gear, but I thought I'd be able to cut it into three and re-weld it together around the output gear. I started off by cutting the backplate from the clutch disc. Then I cut the ring from the frame, cut the ring into three and fitted them around the output gear. I then kept them in place by re-fitting the frame. Once I'd tack welded then fully welded the three peices of ring to the frame, I welded on a long bar to end up with this..... It's not too pretty but I'm not out to win any prizes. This is it on the output gear ready to hold while I undo the low pressure valve nut. It worked really well, so once the nut was off I could carefully remove the housing. So once I'm sure anything else needing removal is done I'll be splitting the block from the gearbox, which I'll be doing when I get a bit of spare time.
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Post by clambod on Feb 5, 2015 16:01:52 GMT
I like the lateral thinking with the "special tool". Interesting and well done
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Post by wimfournier on Feb 5, 2015 17:11:24 GMT
Stu, I am as far as you are dismantling my engine / box unit. I bought a Mini Matic in september and I was that much interested in what the engineers at AP had thought out, that I bought a second engine/box to open it up and look into the insides. I'm very curious to find a lot of 'mud' after all those years. You don't know how frequent all the earlier owners refreshed the oil, afterall. Not that often, I suppose.
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Post by Stu on Feb 5, 2015 17:11:48 GMT
I like the lateral thinking with the "special tool". Interesting and well done Thanks Clambod. I don't know what I'd have done if it'd not worked. The BMC tools are like hens teeth these days I'm hoping to split the block very soon so I'll update once I've done it
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Post by Stu on Feb 6, 2015 15:14:14 GMT
It was a bit 'cool' in the garage last night but I did manage to do a little bit before I got too cold. I removed the oil feed pipe from the transmission and oil pump, the oil filter and housing, and the engine oil feed pipe. Removing the oil feed pipe from the oil pump. Oil filter and housing removed. I then removed the pully hub and timing chain cover. That was as far as I got before jack frost made me go back in the house to warm up
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Post by Stu on Feb 6, 2015 16:21:58 GMT
Stu, I am as far as you are dismantling my engine / box unit. I bought a Mini Matic in september and I was that much interested in what the engineers at AP had thought out, that I bought a second engine/box to open it up and look into the insides. I'm very curious to find a lot of 'mud' after all those years. You don't know how frequent all the earlier owners refreshed the oil, afterall. Not that often, I suppose. Yes I agree. The remaining oil that drained from mine after I'd removed the feed pipe connection was as black as your hat. I recon I'll find lots of sludge in the transmission sump once I've split it from the block
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Post by jockduck on Feb 6, 2015 23:17:28 GMT
Hi, you are going well, I made my own tools too, its all basic 1960's engineering. to hold the T/C spline I wrapped a strip of 1/8" alloy around the spline and then used a stilson wrench! worked fine and no damage except to the alloy. Apart from worn bands, clutch plates and seals the main problem area in certainly the early AP box is the forward clutch, the shaft seal rings wear and jump out and get broken, later boxes have a beefier shaft and should not suffer as bad but check the shaft grooves are square and no rounded edges. One other area is the output gear bearing housings, the small gear that drives the large diff gear. The bearings frequently come loose in the housing and spin wearing the housing and destroying the preload that the bearings need, you will have to source a couple of special spanners for the nut and clutch plate spline, give the nut a bit of heat before trying to unscrew and don't damage the case with your spanners. The bearing/housing should be OK with loctite but you will need to re-do the shimming for the bearings before reassembly. Hopefully a bararian has not got to the box before you(early ones seem to suffer most) and repair and rebuild will be straightforward. Jock
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Post by Stu on Feb 8, 2015 21:13:35 GMT
Hi, you are going well, I made my own tools too, its all basic 1960's engineering. to hold the T/C spline I wrapped a strip of 1/8" alloy around the spline and then used a stilson wrench! worked fine and no damage except to the alloy. Apart from worn bands, clutch plates and seals the main problem area in certainly the early AP box is the forward clutch, the shaft seal rings wear and jump out and get broken, later boxes have a beefier shaft and should not suffer as bad but check the shaft grooves are square and no rounded edges. One other area is the output gear bearing housings, the small gear that drives the large diff gear. The bearings frequently come loose in the housing and spin wearing the housing and destroying the preload that the bearings need, you will have to source a couple of special spanners for the nut and clutch plate spline, give the nut a bit of heat before trying to unscrew and don't damage the case with your spanners. The bearing/housing should be OK with loctite but you will need to re-do the shimming for the bearings before reassembly. Hopefully a bararian has not got to the box before you(early ones seem to suffer most) and repair and rebuild will be straightforward. Jock Thanks for the advice Jock. I'll be sure to check back to your comments when / if I get there. Mines from a 1984 so it's not an early box. It looks like the oil pump may have been replaced, or some other work done with the convertor housing removed because I found a date scratched onto the oil pump cover plate (17.04.1991). It seems a bit soon to have work done after only 6 years though. So at least I know something was done around that time, hopefully not by a barbarian
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Post by Stu on Feb 9, 2015 20:35:20 GMT
I had a bit of trouble removing the cam shaft gear, it was well and truly stuck on the shaft, so I thought it'd be best to split the box from the block first, then remove the cam shaft with the gear in one go. Took a few pics of the gearbox assembly too...... The Governor ....... and a photo of the block, crankshaft, big end bearing caps and con rod bearing caps ....... Removing the long screws from the oil pump ...... Oil pump and gasket removed to expose the end of the cam shaft (slightly pushed in in the photo) with the slot which engages onto the oil pump to drive it ..... Timing chain, gears and cam shaft being removed from the crank shaft and block ....... As above ...... Cam shaft and timing gear removed from block. Just need to get the cam gear off the shaft now ..... So I managed to tap the cam gear off (very very gently) with a hammer working around the shaft. I've not known one to be so tight onto the cam shaft before. Normally they just slide right off like the crank shaft gear did. I'll need to fix it because if I need to change the timing chain with the engine in the car I wont be able to because I'll never get the cam gear off. I'm not sure if it's just tightning on the woodruff key or the shaft itself, so I'll take out the key and see if it's any better. If not I might need to try a bit of emery paper to prevent it locking onto the shaft. The cam lobes and tappets are in really good condition with no significant wear, so I'm please about that, and might show (if they're original) that the engines not been to the moon and back. Tonight I'll be removing the timing cover backplate, pistons and con rods, and the crank shaft. Hopefully I'll then have a stripped block ready to clean up and paint, but I'll be getting it re-bored and cleaning out the waterways and oilways before I paint it (a mistake I made on a manual I'm working on where I've painted it and still have to have it re-bored yet Ah well, its only rubbing down and re-painting. I'll post up some more progress once I've done anything significant. Thanks for looking.
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Post by clambod on Feb 10, 2015 8:03:17 GMT
Looks like you have been busy. At least you will know you have a sound engine and box when it goes back together
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Post by Stu on Feb 11, 2015 10:56:57 GMT
I've just got off the phone with JPat. I called to enquire about their basic and master overhaul kits. I spoke to a very helpful and friendly guy who went through the prices and whats included in each kit, so I'm a bit more educated on where to go from here now. He did say it would probarbly be best to dismantle the components and make a list of whats needed first then order it all in one go. I asked if there was anything which was unobtainable from them, and it seems the only thing he'd have trouble with would be a Sprag Clutch (part of the gear train assembly I think). I'll be posting up some more pics soon as I've now started work on the box
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Post by Stu on Feb 11, 2015 17:19:57 GMT
Last night I completed the stripping down of the engine block. I started by punching identifying dots into the caps and con rods of the pistons so I dont get them mixed up. and then started to remove the con rod caps from the crank shaft ..... First piston assmebly out ..... There is a little bit of scoring to the bearing shells but nothing too alarming ..... Pistons, con rods & caps all out and re-assembled ..... Crank shaft next up .... So its all disasembled. It'll be like this for a good while so I'll cover them in oil and wrap them up for protection for now ...... Moving onto the box, aparently I need to put a special tool into the box to hold back the forward clutch while removing the Governor and auxillery pump, so as I dont have tool 18G 1097, I'll have to use something else Took off the front panel to reveal the valve block and servo unit ..... Close up of servo unit ..... In the photo you can make out the three oil feed pipes running from the valve block to the pistons of the servo unit which tighten the brake bands ..... That's as far as I've got, but I'm going to try and sneak in the garage tonight with a beer to do a bit more Thanks for looking.
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Post by Stu on Feb 14, 2015 22:25:07 GMT
I've now got the whole box stripped with the bits and bobs stored in boxes and covered over. I started by removing the Governor and auxillery pump and held back the forward clutch with this bar I bent into a U shape .... Governor housing assembly removed ..... to reveal the forward clutch etc ...... Forward clutch removed ..... Next to remove was the forward output shaft and reverse shut off valve (located in the end of the shaft). This is the gear to the far right, which I pulled to release the shaft ..... Shaft partially removed ..... and removed ..... This is the reverse shut off valve drawn from the centre of the shaft ...... and the piston fitted to the forward clutch which it connects to when assembled ..... Gear train removed with thrust washer and needle thrust bearing retrieved ...... Here you can see the brake bands in-situ which are connected to the servo pistons, which is connected to the valve block oil pipes ...... Top and reverse clutch removed from the gear train ....... Valve block and servo unit removed ..... Brake bands removed ..... Differential assembly removed ...... Gearbox with diff housing removed ..... Gearbox with everything out ...... I think I'm going to do a dummy overhaul on everything so I can get a complete list of what I need, then order it all from JPat in one go. I'll then go through and overhaul everything properly before re-building the box and engine. This will all take time, as I'm currently restoring my Mini 25 bodyshell, and also have an 850 on the road I need to do bits to, so I'll just have to fit it in when I can. Thanks for looking. I think I'll start by taking the Governor and auxillery pump to bits and overhaul that next but I'm unsure when it'll be. Not too long I hope.
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Post by jockduck on Feb 14, 2015 23:45:38 GMT
Hi, still going well, be careful with the order of the thrust washers in the gear stack and shaft, I have come across a couple of boxes where they have been mixed up. The gear stack is usually very robust, I usually leave well alone, the bands still look like they have some material left better than some I have seen. At least one piston looks very bad probably why the box looks a bit sludgie, I assume the engine was running poorly and burning oil the valve block probably sticky too, carry on!
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Post by limby2000 on Feb 15, 2015 7:31:40 GMT
Omg, when you sent me the link for this I was only expecting a partial strip down, but you,ve proper dived in!.Did you come across any obvious worn out components?.what were the symptoms of your autobox prior to dismantling?.Also of the 3 boxes I have to play with, the 2x 998 gearboxes both from 1989 cars with 45 and 46 thousand miles on them, they have the same black/brown burnt oil tarnish which yours has, where has the 1275 box from a 93 looks immaculate inside, and wondered if this was because it had a left hand side crankcase breather. Great thread!
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Post by Stu on Feb 15, 2015 12:53:52 GMT
Thanks Jock. Very helpful. I know who to ask if I get stuck (hope thats ok).
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Post by Stu on Feb 15, 2015 13:06:43 GMT
Omg, when you sent me the link for this I was only expecting a partial strip down, but you,ve proper dived in!.Did you come across any obvious worn out components?.what were the symptoms of your autobox prior to dismantling?.Also of the 3 boxes I have to play with, the 2x 998 gearboxes both from 1989 cars with 45 and 46 thousand miles on them, they have the same black/brown burnt oil tarnish which yours has, where has the 1275 box from a 93 looks immaculate inside, and wondered if this was because it had a left hand side crankcase breather. Great thread! Hi Limby, I find that I can read the manuals all day long but it only really makes sense when you actually get stuck in and open it all up. I've not found any obvious damage or serious wear to anything, but I need to inspect everything properly during the component overhauls. I dont know anything about the engine prior to me aquiring it, except the usual 'it was running fine' stuff. I think the discolouration is likely to be due to a combination of a few things like insufficient oil changes and poor engine running / burning oil as Jock mentioned. Ive not considered the crankcase breather position but I guess it could contribute.
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Post by clambod on Feb 16, 2015 9:26:01 GMT
That's one hell of a job you've got there. Totally different to a manual box, which is much simpler. I'll follow this with interest.
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Post by Stu on Feb 16, 2015 14:05:05 GMT
That's one hell of a job you've got there. Totally different to a manual box, which is much simpler. I'll follow this with interest. Thanks Clambod. I'm not sure when I'll be updating as I'm back working on the bodyshell now. I'll post up any progress as and when I do it. Stu.
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Post by 1982minihl on Mar 7, 2015 23:39:15 GMT
Very interesting read, looking forward to more progress particularly interested in forward clutch.
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Post by Stu on Mar 8, 2015 15:42:45 GMT
Thanks. I'm not sure when I'll be back on it now because I've just shelled out on the new panels for the full front end and I'll be busy on the bodywork through the Spring & Summer and also have a manual 850 on the road which needs some minor paintwork repairs doing before the Summer shows. I'm committed to overhauling the auto box and engine to put it in Felix though. It'll probarbly be this Autumn when I start back on it. Hows yours going ? Any progress ?
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Post by Stu on Apr 29, 2015 15:02:40 GMT
I've decided to post progress of my Mini restoration here so I can keep it all in one place. As my plan is to fit the overhauled auto box (when I get time to start it) and engine in Felix (Mini) it seems sensible to follow on with what's taking all my time up now. In fact I'll probarbly (assuming the Admins dont mind) use this project page as a record of work I do on my other Mini too (an 850 manual) I'll copy and paste / import the nesessary to get up to speed from when I started Felix to where I am now, and will continue to post up my progress from now on. If anyone reading wants to say hi, ask a question or just watns a natter please feel free to post here anytime
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Post by Stu on Apr 29, 2015 15:24:08 GMT
10 November 2014. I thought that it would be good to have a record of work to look back on, so I've decided to keep a journal of progress with my Minis. I've got a 1979 850 which I'm trying to lightly restore without a full stripdown, and that's going well, and I've recently aquired another Mini, this time a 998 Auto which came in bits with the shell partly done. It's had a lot of patch repairs, some not too bad and some quite shocking. It was not supposed to be a quick fix, as I wanted something to keep me quiet for a good few years, so it's all good really. Below is Molly, my 850, currently just passed MOT and back on the road. I've done a lot to it over the past 18 months, recently tidying up the engine and engine bay. And this is Felix below. I'll be due to start on him very soon, but need to make / buy a rollover jig before doing too much, but I''ll see how it goes for now. I've got a complete car, it's just all squirelled away wherever I can store it all for now, but I'll be concentrating on the shell till it's finished before doing anything else, and I recon that'll take a few years.
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Post by Stu on Apr 29, 2015 15:41:22 GMT
15 November 2014. Started stripping off whats left of the sound deadenning to the tunnel and rear seat panel. Found some small areas of corrosion. This shells had lots of patch repairs with filler plastered over the welds instead of grinding them back. I suppose this is understandable as the interior would still have been in if local patches were done so grinders would be a no no due to the fire risk from the sparks. Below is a photo of the drivers side arch repair. Looks like the corrosions been cut out and a new section planted on from the outside. Some of the fillers pretty thick in places. Here at the floor to arch section its about 6mm thick, or should I say was, as Ive removed it all now. Ill need to strip everything back on the whole shell to see whats been done and whether Ill need to take it out or not. This inner sill repais not too good. Its been welded on the top flange with the door step but its bare minimum welding to say the least. I know Ill need to take out the floor edge, inner and outer sill both sides and fit the full replacement section from M machine. Lots more to come I think.
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Post by Stu on Apr 29, 2015 15:52:55 GMT
The curse of oversills strikes again. Looking forward to cutting the things off eventually. Not done much more apart from making some bridge ramps to stop the castor wheels dropping into the gravel in front of the drive when I roll out the shell. I'm hoping my rollover jig will be delivered tomorrow from Handling Solutions I'll need to get it painted before mounting the shell on it so I'm hoping it'll be delivered in the morning.
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Post by Stu on Apr 29, 2015 16:01:17 GMT
4 December 2014. Parcelforce delivered my rollover jig this afternoon. If I've got time tomorrow I'll paint the parts before assembly. So before I put the jig together, I painted it with Bonda Rust Primer with zinc, to stop the metal developing surface rust. Then I made up the A frames. I also bought the castor set as I wanted the jig to be mobile so I can roll it in and out the garage. I've got to say I'm very impressed with the jig. The shell sits very high, which has given me a few headroom issues in the garage, but nothing I cant get over. It's all very very solid, spins really easily and is perfectly balanced in all positions. It certainly wasnt the cheapest jig out there, but im more than happy with it bearing in mind the shell will be on it for a few years. I can also spray the shell while its on once I've completed the bodywork.
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Post by Stu on Apr 29, 2015 16:02:56 GMT
7 December 2014. While the roads were dry, I decided to take Molly out for a spin this afternoon.
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Post by Stu on Apr 29, 2015 16:06:37 GMT
7 December 2014. Started working on Felix this afternoon after working out the best position for the jig in the garage. The clearance between the shell and the electric door motor is a bit tight with 20mm gap when rolling over. Bearing in mind I didn't check the jigs critical clearance dimensions I think I've been very lucky ! Started by removing the existing hammerite from the front offside inner arch. I knew there were some patches in there but found quite a few when I got it all stripped back. Even though the repairs seem fairly good, they are plates over the existing arch which I dont like so will need to cut it all out and fit new panels. I also had to remove filler which was plastered all over the place, presumably to give a smooth finish to the arch. In places it was literally 6mm thick ! This is the bottom corner between the arch and footwell. I recon I'm likely to find a lot more of this. I also did a bit of exploring on the outside of the floor with a scraper tonight. Everywhere I dig I'm finding filler pasted over welds of plated repairs. In places, like the battery box its 5mm thick. I think I'll have to strip the entire car and remove all traces of filler! Started stripping off the floor which was suprisingly easy. I'ts just had a thin coat of black hammerite which came off very easilly with a sraper. I keep uncovering patch repairs. Some dont seem too bad actually.
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Post by Stu on Apr 29, 2015 16:09:53 GMT
13 December 2014. Started work on the boot floor today. I started by removing the valance. I was worried I'd cut into the lip of the rear panel but it worked out ok. My suspicions that the boot floor was covered in filler were confirmed as I started to hack it all off. I can't really understand why the patch repairs have been covered so much in filler because the metal below the filler is ok. If the welds were ground down there would have been no need for it. I think once I've cleaned up the boot floor I'll assess it for possible patch repair, but I'm starting to think I'll be needing to put a full new one in as it's had multiple repairs already and some are fairly poorly done. Replacing the full floor might be easier in the long run. I don't know what's been welded in here as a repair, but I can only think it's a section of boot floor from another shell that's been slapped on and badly spot welded in over the existing panel, but it's been really poorly positioned and welded. Anyway I'm going to keep stripping off the paint and filler till it's all gone, and then I'll know where I am and can start ordering some new panels.
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