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2Nd Gear Crunching - Mpi 1999


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#1 Helios

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Posted 17 August 2017 - 10:13 AM

Hi all,

I live in Crete (Greece), I bought the car second hand from Germany with a bit less than 25k miles on the clock, now it is only 30k.
We use it mainly in summer, usually for short rides around the area.
From the very beggining it was that annoying thing with the 2nd gear crunching when downshifting from 3rd with quite high revs, I have to drive the car gently and change the gear slow to avoid the crunch. Sometimes it is crunching from 1st to 2nd as well, unless I am careful and keep the revs down.
Fortunately, up to now, I do not have any gear pop-outs.

I know it is most probably the well known and common MPi gearbox fault (baulk rings fault).
I can live with it (although it spoils some of the fun) but I am trying to find ways to live more comfortable with it.
Do you believe a change to a more thick oil will make my life easier?
A 20w50 everybody suggests for the engine-gearbox classic mini sump is probably a bit thick but remember, it is Crete here (south Mediterranean), we use the car in summers and summers here are hot!
Do you believe a good quality mineral 20w50 oil will help my gearbox a bit on this specific problem?

Edited by Helios, 17 August 2017 - 10:54 AM.


#2 MacGyver

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Posted 17 August 2017 - 10:45 AM

Just to point out, you should ONLY use 20/50 oil in a mini engine unless you have an automatic transmission.
I had the crunching as-well, like lots of mpi's, but is cured by renewing the baulk rings. (a gearbox rebuild is a good idea just to get things on a good starting point)
I thing the rings had too little tolerance so wore out too fast on the later mini's but the high final drive probably had something to do with it too.
I might be wrong on the last bit ad I am no expert but someone will come along with much more knowledge than me I'm sure.

Ben

#3 Helios

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Posted 17 August 2017 - 04:55 PM

Dear Ben, thank you for the reply.

I am sure it is much trouble to take the engine and the box out and fix it.
It needs specialized technicians and lots of money. Although the mechanics who maintain my mini are very experiened in older minis, I know that they lack the experience needed to work with the more complicated injection cars comfortably because there are not many of them here, now or in the past. Remember, it is a south mediterranean island here, far from the mainland of Greece. (The possibility to send the box abroad makes the situation even more complicated..).

So, I am seeking for tips to help me live with this problem less uncomfortably.

Do you think the 20w50 oil will be of any real help?

Thank you all,

Nikos

Edited by Helios, 17 August 2017 - 05:44 PM.


#4 MacGyver

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Posted 17 August 2017 - 07:24 PM

I think it will slow the rate of wearing of the rings and other parts, it will help make the problem not get any worse at least, if not cure it for some time.
The crunching (for me) was worse when the engine was cold and after about 10 min of warming up and careful gear changing it seemed to disappear (being careful anyway) and I seem to recall that going from 3Rd to 2nd while braking was easier to pass without crunching.
I did run my first mini (stupidly)on 10/40 and basically anything I could find even 0/15 and ran for about 10 years of hard driving, altho the coolish weather might have slowed the wear it is now definitely scrap. The engine that is, not the car. 😉
Does anyone els about have some advice on hot weather?

Australians by any chance?... 😀

#5 Helios

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Posted 18 August 2017 - 06:01 AM

I think it will slow the rate of wearing of the rings and other parts, it will help make the problem not get any worse at least, if not cure it for some time.

 

It sounds promising, thank you again!

 

Nikos



#6 minimans

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Posted 18 August 2017 - 06:49 AM

Learn to double de clutch on your down shifts, there's plenty of guides on youtube to learn how and it will stop the crunch and make you sound like a racing driver! Basically you dip the clutch pull it out of 3rd release the clutch and blip the throttle depress clutch and select 2nd gear and release clutch. It sounds like a lot of work but once you get used to it it takes no time at all and if you do it for all down shifts it's a lot kinder on the gear box! for cruching on the up shift ie 1st to 2nd you need to do the same but DO NOT blip the throttle. All your doing in both cases is matching the gear speeds before moving them



#7 Helios

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Posted 18 August 2017 - 07:17 AM

...it will stop the crunch and make you sound like a racing driver!

 

I am already practicing the old good double clutching in secluded areas, it makes my life even harder sometimes  :D  but I guess it worth the effort to master it!

Top quality information here, thank you all very much!



#8 AeroNotix

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Posted 18 August 2017 - 10:32 AM

Proper driving technique is the only solution if you don't want to have the gearbox rebuilt.

 

That said, despite not knowing your financial situation I would definitely recommend guess works. (http://guess-works.com/)

 

My brother's mini had the same issues initially as you (3rd -> 2nd crunching, sometimes 1st > 2nd, etc). Clearly the synchros were well and truly worn out. However, he tried to learn proper technique whilst trying to figure out what to do eventually with his mini. Rev matching and even double clutching if the synchros are not working whatsoever is definitely a solution. Remember that very old transmissions didn't have synchros at all so people had to make do with techniques like that!

 

What prompted us to go to guessworks is that his differential exploded, cracking the case and stranding the car completely. We went to guess works.

 

I have an invoice somewhere but I specifically remember 802.11GBP or something like that for:

 

  • New case (since the diff explosion cracked the case)
  • All bearings and bushings and seals replaced
  • Any worn synchros replaced
  • New 3.44 differential (compared to the 2.7 in the MPIs, a nice little upgrade)
  • Moly X-pin diff, said to be stronger. In fact Guess Works practically challenged us to break it!!
  • New clutch
  • New oil pump
  • All new gaskets
  • Guess work's time
  • New layshaft
  • Centre oil pickup
  • Probably a bunch of other things I am forgetting

 

Our situation was different, GW mentioned that he had a couple of weeks lead time on any gearboxes sent to him and, because I live in a different country to my brother, we needed to meet up to get the engine out. GW offered us to take the engine directly to his work shop on a Saturday and he would rebuild it while we waited. We took the whole power unit to GW and he broke it down before working on the different components. We paid for that service, I believe it would've been cheaper if we just took the gearbox in isolation to him but as we wanted the clutch changing and the whole unit having at least a visual inspection we took the whole thing.

 

All in all, it took only a few hours for GW to rebuild the gearbox and other components. My brother is mostly extremely happy with the service. He might pop up in this thread to give his opinion.

 

Finally, the cost, frankly I don't think you can beat that cost any where. GW is a specialist expert in mini gearboxes and clearly knows his stuff. You would find it extremely difficult to find someone as knowledgeable as he for a similar price. It just doesn't make sense to try to find some no-name garage to carry out repairs on a gearbox they haven't seen in years or probably haven't even touched. In Greece of all places!

 

Stripping a mini to take the engine out is honestly not that difficult. It's all just lego at the end of the day and it would give you the opportunity to rebuild/replace a few other things on the way to getting it out/in. Shipping JUST a gearbox to GW, for me, in Poland (guessing it would be a similar price?) is about 90GBP. On top of the cost for GW to do his thing, it's well under 1000GBP. Depending on the work you need doing it may be cheaper as well! There's an online configuration page on GW's site to choose what you need.

 

SERIOUSLY, USE GUESSWORKS.


Edited by AeroNotix, 18 August 2017 - 10:38 AM.


#9 Helios

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Posted 19 August 2017 - 01:43 PM

AeroNotix, thank you very much for the detailed and very helpful reply.




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