1st Gen R50 Cooper Midland rebuild questions. Worth it?

Why not flush the fluid, refill and drive it a few times and see if you really have an issue first? Sometimes the "other" owner did nothing to the car to keep it in proper running order. A few fluid changes are cheaper than the cost and headaches of a tranny rebuild.

BMW is known to call almost every fluid "lifetime" fluid. In reality they are but only as puddles or spots on your garage floor. :lol:

 

I'm with Dave, drain and replace the gear oil first.

Little tip....

Loosen the top plug first. Sucks when you drain it and then the fill plug is stuck.

 

Red line is not that good and royal pimple is not much better unless you only pan to flush and fill with the cheap stuff to clean out the tranny.

I would use either AMSOIL or Motul. (Links below)

You can also use the lower version 75w-90 if you want.
http://www.amsoil.com/shop/by-product/gear-lube/severe-gear-75w-90/?code=SVGQT-EA

AMSOIL Severe Gear® 75W-140

Motul is great for a car with an LSD and this is what a lot of track cars sware by with OS Giken diffs. (They are not cheap)
http://www.amazon.com/dp/B004LEZPHY/ref=wl_it_dp_o_pC_S_ttl?_encoding=UTF8&colid=1JEWSSABUMWXR&coliid=I2K4H2N908TW7T

 

You can prolong the transmissions life by changing the fluid, but the Midland will meet an inevitable end regardless. They develop a whine like that, and you can go for years, but one day it will decide a job is just too much stress to take.

Modern transmissions have become more of a replacement part, not many suppliers sell replacement parts for them like they used to in the 80's and 90's. Back in my VW days, I blew 2nd out twice and spent about a month and a half total wait time for the parts both times.

The Getrag 5 speed in the later G1 Coopers is a much better transmission, and will physically bolt up to the car, but there will obviously be a handful of other parts required as well as a different flywheel to make it a "bolt on" job.

Hopefully you can get a few more years of life out of it, but once the whine starts, there's no making it go away.

 

It's only a little more expensive to put a Getrag 6-speed into an R50 than the 5-speed Getrag.
Mostly the increased cost of that box. You'll spend about as much on all the other stuff
you need to replace a Midlands with either Getrag.

 

Just remember, the spline count on the CV joints are different for all 3...
So some "extra" stuff will be needed if you go to something other you have...

 

please swap them and send all your Midlands boxes to me! I love the Midlands

 

The Midlands just needs some TLC The problem is that the Midlands needs rebuilding early and is not a 300,000 without touching it box. The design is from the 80's so not the best as it was designed to be used with low powered lightweight 1.4L french cars.

I quite like that the box is lightweight, comes with a ton of low final drive options and is quick to remove, rebuild and replace. Hopefully the straight cut gear set I've just bought will fix the issues.

 

I know this is old but I will vouch for John in any way. Sent me a rebuilt box w/ clutch kit and all has been well. I still haven't gotten around to busting open my old one but intend on keeping it as a spare.

The whine you mention is funny, my old one had it and my new one has it. I can't comment on the differences but it seems to be working perfectly. There is what seems to be a bit of chatter that goes away when the clutch is pressed as well. I attribute it to road noise at this point.

They're odd little cars but they're really a blast. The issue with the box sucks but my car made it 90k ish miles and then one day while stopped at a light I came off the clutch, the car moved a little and then it popped.

 

John is a really nice chap, he is one of my supporters supplying all the gears I need. He builds around 20 to 30 Mini, Peugeot ,Rover MA boxes a week. He's breaking Mini's too to gain the much needed spares. So I would say he's good at rebuilding Midlands boxes..LOL

Regarding the rattle. That's going to be the selector shafts rattling. At first I thought it was the input bearing rattling in the housing so on one of my many rebuilds I made sure the bearing was tight by dot punching the bearing housing. The rattle was still there but if I moved the gear stick slightly without dipping the clutch the noise went away which rules out the bearing.

As the whine, mine has always whined, I guess that must be one of the quirks of this box.