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Post by dhorsler on Mar 23, 2017 21:23:27 GMT
My SPI Mini auto gearbox failed suddenly last week, it was working fine and whilst i was in stop/start traffic, i attempted to pull away and instead of pulling smoothly it juddered violently but still pulled away and changed to second gear as normal and didn't judder any more thereafter, drive/grip was normal.
However, the next time i stopped and attempted to pull away, the juddering was much worse and then before gaining any significant speed, drive was totally lost and the engine revved freely thereafter.
Now, drive in all gears (including reverse) has been lost, putting into any gear sounds like its going to work as in there is a bit of a clunk like normal and there is a very slight amount of drive but then the engine just revs up with not enough drive to move the car.
Oil level is normal, no forward or reverse gears provide any drive other than a slight binding when initially put into gear, it fades thereafter.
I initially thought it was most likely to be the forward clutch fallen to pieces, but having done lots of research, I believe it would still have had reverse drive working if this had happened?
Has anyone got any bright ideas of what may have happened to it?, I've yet to pull it apart and see what's happened.
I've ordered a pressure gauge but it hasn't arrived yet so not tested oil pressure yet.
Has anyone had any experience of torque converter failure?
To be fair it has been leaking oil recently from bottom left hand end of the gearbox/transfer case area, its entirely possible the crank seal is leaking i guess, or torque converter seal come to that.
Any suggestions of where to look first greatly received.....
cheers dave h
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Post by limby2000 on Mar 24, 2017 20:34:37 GMT
Hi Dave your doing the correct things, checking oil,and pressure.Also check gear selector cable just to be sure. As you say losing forward and reverse also seems pretty terminal. My gut feeling its not t/c. The growling to me sounds clutch related. Perhaps other can give their view,s. Regards Terry.
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Post by 69hcode on Mar 25, 2017 4:04:47 GMT
I wonder if the low pressure valve for the torque converter is bad? Not sure what would happen if it went out. Sounds like it's right where the leak is.
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Post by limby2000 on Mar 25, 2017 21:29:02 GMT
Good call, it would explain the loss of drive, however not sure about the sound indicated. As for the leak, dont all mini engine,s leak,lol.
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Post by dhorsler on Mar 26, 2017 20:32:13 GMT
unfortunately didn't get chance to measure pressure this weekend, will try and do so one evening this week.
did give it another quick try though, it definitely produces momentary drive when you first put it in any gear and then fades to nothing within a few seconds, taking out of gear and putting back into gear gives momentary drive again before fading away, no horrible noises or anything.
checked for oil leakage though and it does look like its coming out of the torque converter cover at the bottom as well as around the diff somewhere, but this was leaking before it failed, driveshaft seals etc. need replacing. Will check engine breather pipes aren't blocked with goop when i get a chance.
suspect oil pressure test is crucial at this point....
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Post by limby2000 on Mar 27, 2017 20:48:53 GMT
Mmmm sounds like there is a connection with the oil leak, how much you losing and have you got sufficient oil in at moment, they are fussy about their oil level. Pressure test seem the way forward. If your testing the gearbox working pressure from the test outlet on the oil filter housing you will need a gauge that can read 200 psi.
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Post by mra-minis on Mar 27, 2017 22:09:31 GMT
unfortunately didn't get chance to measure pressure this weekend, will try and do so one evening this week. did give it another quick try though, it definitely produces momentary drive when you first put it in any gear and then fades to nothing within a few seconds, taking out of gear and putting back into gear gives momentary drive again before fading away, no horrible noises or anything. checked for oil leakage though and it does look like its coming out of the torque converter cover at the bottom as well as around the diff somewhere, but this was leaking before it failed, driveshaft seals etc. need replacing. Will check engine breather pipes aren't blocked with goop when i get a chance. suspect oil pressure test is crucial at this point.... This is a low pressure issue, so can be a long list of causes, my first question is please explain how you check the oil level ? This is very much more important than people often think. The pressure check is next, in between do not drive or try to as this will only cause more issues later.
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Post by dhorsler on Mar 28, 2017 13:21:37 GMT
Hi,
Oil level was checked by placing Mini on a level surface, leaving oil to drain from around the engine fully and then using the dipstick as per normal, cleaning and repeating several times to ensure the same result, oil was initially towards the lower mark since its been leaking quite a lot recently so i added more oil to bring up to the max mark, didn't make any difference unfortunately. I presume this is the most accurate method and i'm not missing something obvious?
The engine oil light never came on but they trigger at such a low level anyway, of little use half the time..... The car doesn't have an oil pressure gauge unfortunately, I might well fit one now though....
I presume the oil pressure is used to engage the clutches/drive?, also the brake bands etc.?, so no pressure = no drive.
I guess you are thinking of a significant oil pipe leak somewhere within the gearbox itself thereby reducing the overall pressure obtained?, is this a common failure?
Come to think of it, if the engine oil pressure bypass ball valve sticks open then i guess it will reduce the gearbox pressure obtained also?
I will try and take the pressure reading tonight after work if i can find a few spare minutes to do so
Thanks for the replies thus far
cheers dave
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Post by mra-minis on Mar 28, 2017 19:29:31 GMT
Hi, Oil level was checked by placing Mini on a level surface, leaving oil to drain from around the engine fully and then using the dipstick as per normal, cleaning and repeating several times to ensure the same result, oil was initially towards the lower mark since its been leaking quite a lot recently so i added more oil to bring up to the max mark, didn't make any difference unfortunately. I presume this is the most accurate method and i'm not missing something obvious? The engine oil light never came on but they trigger at such a low level anyway, of little use half the time..... The car doesn't have an oil pressure gauge unfortunately, I might well fit one now though.... I presume the oil pressure is used to engage the clutches/drive?, also the brake bands etc.?, so no pressure = no drive. I guess you are thinking of a significant oil pipe leak somewhere within the gearbox itself thereby reducing the overall pressure obtained?, is this a common failure? Come to think of it, if the engine oil pressure bypass ball valve sticks open then i guess it will reduce the gearbox pressure obtained also? I will try and take the pressure reading tonight after work if i can find a few spare minutes to do so Thanks for the replies thus far cheers dave Hi Dave, The oil level isn't checked that way,,, there is a very specific method that is possibly why you think your oil level is ok, search this forum for correct oil level it explains it fully in great detail and explains why you must follow this method The engine oil pressure gauge has no relevance to the transmission oil pressure except if either one is at zero then both will be at zero.... Install 10W/40 MA2 spec is best well worth the extra money
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Post by mra-minis on Mar 28, 2017 19:31:14 GMT
I can be contacted on martin@kmprecisionengineering.com
The transmission pressure take offs are 1 on the auxiliary pump and the other on the filter head
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Post by dhorsler on Mar 28, 2017 20:13:36 GMT
Hi,
I've taken pressure readings at the filter take off, surprisingly the results were as follows:
idle in neutral, about 100psi first gear about 100psi drive between 100 and 120psi reverse 170 to 180 psi
I believe these results are about normal/expected?
thanks Dave
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Post by mra-minis on Mar 28, 2017 20:16:31 GMT
I can be contacted on martin@kmprecisionengineering.com
When you took the readings was it hot or cold ?
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Post by dhorsler on Mar 28, 2017 20:21:09 GMT
I haven't been able to measure the auxiliary pump pressure, what kind of pressure reading is normal for that pump?
More importantly of course, what does the auxiliary pump drive?, information on the inner workings of the hydraulics within the gearbox seems hard to come by, i've yet to find a decent publication on how everything within the gearbox works, just bits of info scattered across various sites.
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Post by dhorsler on Mar 28, 2017 20:21:58 GMT
oil was stone cold, its too late to warm it up now, noisy exhaust, sleeping child lol
on the plus side, i found one of the oil leaks, coming out the end of the oil pressure switch....
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Post by limby2000 on Mar 28, 2017 20:53:45 GMT
Yeah most of the automatic literature was pre 80,s as it was deemed far to complex for your average grease monkey,lol. Most manual,s after that just say contact auto sprcialist,s.
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Post by dhorsler on Mar 28, 2017 21:22:12 GMT
I have just managed to find a website that gives a detailed explanation with oil flow diagrams and what clutches/bands lock for which gear etc. which is really most interesting and also somewhat disturbing at the same time lol, I can now see how its possible to easily lose forward gears and not reverse gear but to lose all gears like mine indicates a failure to lock either of the forward and reverse clutches properly or no torque from the converter.
Since i have slight momentary drive, it indicates its not a terminal planet gear dropped off kind of issue, still no guarantee the torque converter is providing any decent grip though, shame you can't look inside whilst its running and see if the transfer gears are turning, although testing the auxiliary pump pressure will probably give a decent indication of this since ultimately its driven from the torque converter output ......
I'll see if i can find the auxiliary pump measuring point tomorrow evening and measure that, I would hate to strip the whole thing to pieces only to find out it was the torque converter after all and i didn't have to, that's my normal kind of luck :-)
no point rushing into stripping it apart until i know exactly what i'm looking for, might miss something, put it back together and find its exactly the same lol, that would be the worst feeling ever, I do need to make some progress on it though, I have other Minis to get roadworthy before the show season starts in earnest, then i won't have any spare time at all....
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Post by mra-minis on Mar 29, 2017 0:01:46 GMT
I can be contacted on martin@kmprecisionengineering.com
lol, I don't think you do.... I will lay a bet of £4.50 that it's either one or both planetary gears, its classic just enough to "get" some movement but not enough to drive
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Post by dhorsler on Mar 29, 2017 8:19:46 GMT
Only £4.50 lol
How do the plant gears break?, do they split between two teeth and then twist sideways?, wouldn't it make a horrible noise if it was slipping teeth or not engaged properly? it makes no unusual noises at all.
I presume you can't tell this without a complete strip down?, i.e. you can't see anything if you remove the front cover and valve gear etc.?
Which planet gear normally fails?, the one that is attached to the shaft feeding the two clutches I'm guessing to lose all drive?
I'm resisting yanking the engine out and stripping it down right now because I know I'll just not give up on it until its fixed and spend hours tinkering with it and it will stop me working on the metro cabrio restoration which i really need to get finished asap otherwise it will just sit there for ever blocking on the other 5 minis we have lol
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Post by mra-minis on Mar 29, 2017 10:14:15 GMT
I can be contacted on martin@kmprecisionengineering.com These are broken......
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Post by notamini on Mar 29, 2017 12:54:47 GMT
Dave H, Have you looked at the available literature on this site? Is there anything there that you haven't read? Last ditch effort is to hunt and hunt online for the book. It is expensive and extremely rare but tells you all you will ever need to know. 85 BPS is a good price but it can easily go int 3 digits. The book is by Foulis. Read the thread called Manuals and Leaflets. It tells you where to download and what there is available.
Mark Ontario, Canada
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Post by dhorsler on Mar 29, 2017 14:35:18 GMT
no i hadn't seen that thread, thank you, like most forums, if you don't know exactly what to search for and its not obviously visible then you miss it if you haven't got many hours of spare time to go trawling through every post....., or sometimes even if it is obviously visible you just gloss over it lol, the foulis manual sounds exactly what i need, I shall obtain a copy and pull it to pieces or vice versa. I suspect the chances of Martin being correct on this one are pretty darn high Only one way to find out...... sadly though it might have to wait a few weeks until i have time to do it.....
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Post by notamini on Mar 29, 2017 15:39:07 GMT
Could you please post a picture of your Metro Cabrio?
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Post by mra-minis on Mar 29, 2017 15:52:32 GMT
no i hadn't seen that thread, thank you, like most forums, if you don't know exactly what to search for and its not obviously visible then you miss it if you haven't got many hours of spare time to go trawling through every post....., or sometimes even if it is obviously visible you just gloss over it lol, the foulis manual sounds exactly what i need, I shall obtain a copy and pull it to pieces or vice versa. I suspect the chances of Martin being correct on this one are pretty darn high Only one way to find out...... sadly though it might have to wait a few weeks until i have time to do it..... Well it is really a case of time and money as there is quite a bit of AP2 experience on here, and as for tooling and parts I can supply you with any of those that you require as I make most now.
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Post by dhorsler on Mar 29, 2017 20:03:50 GMT
thank you Martin, I'll be in touch if I struggle to fabricate suitable tools :-)
I could obviously convert it to manual but the auto is so quirky and fun, it has a certain appeal that i want to keep it original if possible....
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Post by limby2000 on Mar 29, 2017 21:32:12 GMT
Keep it auto, it wont be your cheapest option, but their becoming more scarce all the time.
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Post by limby2000 on Mar 29, 2017 21:34:55 GMT
I can be contacted on martin@kmprecisionengineering.com These are broken...... View AttachmentHow are they joined at factory Martin?.
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Post by mra-minis on Mar 29, 2017 23:47:58 GMT
I can be contacted on martin@kmprecisionengineering.com
Originally it was double sided tape.... the early ones where welded but were not so good, the later gears are laser welded and a lot better also slightly bigger so don't try to swap them over....
The gears irrespective of which ones you have MUST be swapped out in matched pairs do not try to mix them up as in most cases it will end in tears, because they have to be timed together..... on the edge you should see a line with an arrow or on early gears a line and a cross. these have to line up with the yoke to carrier mating face
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Post by mra-minis on Mar 30, 2017 0:56:55 GMT
..., I'll be in touch if I struggle to fabricate suitable tools :-) I could obviously convert it to manual .... First you want to steal the food off my table then you want to murder a perfectly good automatic Mini ? ok guys down tools ! Yes if you find your fabrication skills are tested to the limit and beyond I will be only too happy to help Dave.
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Post by dhorsler on Mar 30, 2017 20:59:17 GMT
ha ha, don't you fret, it will stay as an auto one way or another, i have a complete spare carb 1275 auto engine and gearbox tucked away for emergencies if the worst comes to the worst lol as requested, picture of the metro (rover), it looked reasonable initially but fell apart completely when i touched it lol, been welding for weeks and weeks now.... its the same age as the broken auto mini, 1995
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Post by mra-minis on Jul 26, 2017 8:41:08 GMT
I can be contacted on martin@kmprecisionengineering.com
As that is a 95, shouldn't it have a "K" series engine fitted ?
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