Crunch into reverse

Drew20

Drew20

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I'm fairly new to my CSL, and it makes a crunch into reverse every time. I put this down to a dragging clutch, but I've been over the system and it all seems fine. The garage tells me that a crunch into reverse is normal and I should live with it, however this doesn't sound right to me. Typical garage cop out.....
So:
Who's gearbox crunches into reverse, normal or not?

Another symptom is that second can be hard to get on a downshift, and first is very hard to get if the cars stationary, but ok to get if the car is moving slowly (i.e. drop into first as you approach the lights). 3rd and 4th are both ok.
This is with the factory 4spd box

Thanks
 
I have the same experience when downshifting from 1st to 2nd at low speed’s it does not seem to appreciate it. I’ve never had this and other cars before


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1st gear is not synchronized in the early 4 speed of my 2000CS. To keep from crunching as I roll to a stop with the clutch depressed, I will cycle from 3rd to 1st. No crunch.

Your Getrag is likely a later box. Have you changed the fluid in it? That typically solves a lot of these symptoms.

Ed
 
Sounds like clutch isnt fully separating? Should be no crunch in any gears including reverse.
 
Stevehose said:
Sounds like clutch isnt fully separating? Should be no crunch in any gears including reverse.
Click to expand...

That’s what I would’ve thought as well and why I thought it is odd. I will forward this string to my mechanic is working on the car now


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Unless the synchro is worn on 2nd gear which is not uncommon. Worn reverse synchro would be very uncommon

scottevest said:
That’s what I would’ve thought as well and why I thought it is odd. I will forward this string to my mechanic is working on the car now


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Click to expand...
 
The transmission was converted back to standard from a dog leg 5spd by the garage as part of the sale. So a new clutch and new fluid too. Box was not rebuilt but was a "good one".
My first thought was air in the hydraulics but I've checked that and that is rock solid, but yes it still feel like clutch drag.
Garage is a reputable classic BMW dealer, but I've had no joy in getting them to recognise the issue let alone fix it.
A new master and slave is not expensive, but access is rubbish to the master cylinder.... not keen to do this without a good chance of success

Thanks for all replies, much appreciated
 
Have the shop remove the slave cylinder from the bellhousing and bleed it that way.

Drew20 said:
The transmission was converted back to standard from a dog leg 5spd by the garage as part of the sale. So a new clutch and new fluid too. Box was not rebuilt but was a "good one".
My first thought was air in the hydraulics but I've checked that and that is rock solid, but yes it still feel like clutch drag.
Garage is a reputable classic BMW dealer, but I've had no joy in getting them to recognise the issue let alone fix it.
A new master and slave is not expensive, but access is rubbish to the master cylinder.... not keen to do this without a good chance of success

Thanks for all replies, much appreciated
Click to expand...
 
Hi, some one on the forum suggested replacing the Gear oil with automatic Transmission fluid, may want to check it out for sure!
Did you give up a Dogleg tranny for regular 5 speed?
 
I tried to get the slave out to bleed it but on the earlier set up the slave fits through a hole in the bell housing and it can't come out without disconnecting the flexi hose (if I have the system apart at any point I will put a longer flexi hose on it to get around this in future). But I don't think the hydraulics is the issue as the slave and master are solid when I tested them. I put a g clamp on the slave to stop it moving and the clutch master was solid, once the piston was past the reservoir port.

I gave up a dog leg box for a factory original 4spd box

So crunch is definitely not normal, I'll be back to my garage and make my point a bit better

Edit: I've used redline mtl on a manual 635csi to good effect, but the shift on that was never as bad as the CSL is now, I think it's more than just worn synchros
 
It could be down to wrong oil in the box, try the redline or just ATF to see if it is better, a lot cheaper than a new gearbox, I have lost count of the times people brought a used gearbox back to me under warranty due to 2nd gear selection issues, changed the oil for a special manual fluid instead of the gear oil they had used and job done, Pat
 
It shouldn't crunch at all. Below is my experience with my CSL 4 speed. It took me a while to figure out the optimal way to use it:

- You need to be at a complete stop and you need to engage the clutch 100% fully, wait a second or 2 and then move into R gear gingerly and very slowly (because no R sincro).

- Do all other gear changes with full clutch pressure (push very hard down to floor). Don't rush the gear changes. I find the CSL box doesn't really appreciate high speed downshifts into 2nd.

I have made these adjustments to the way I use my CSL 4 speed gearbox and no problems now. I also only wear driving shoes so I can really feel the engine revs and clutch operation and to be as one, and more connected with the car.

These grand tourer E9s don't seem to like to rush anything much.

On other cars I can make gear changes much faster. I find the CSL gearbox far less racy than other boxes such as on old Alfa's and Porsches. But it is a very strong tough gearbox that feels smooth and confident, and is wonderful when you get it right.
 
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My first thought was the same as Pat Hooks; change tranny fluid to Redline and try again.
 
my experience is that you have to be at a complete stop, then push the lever halfway there, then all the way.

Alternatively, stop, shift to first, then to reverse.

It's just one of those "they all do that" things the Hans and Birgit inflicted on us poor mortals, one afternoon after having several biers.
 
Ah ok you have the cylinder shaped slave, yes, that can be bled in situ but sounds like you've covered that.

Drew20 said:
I tried to get the slave out to bleed it but on the earlier set up the slave fits through a hole in the bell housing and it can't come out without disconnecting the flexi hose (if I have the system apart at any point I will put a longer flexi hose on it to get around this in future). But I don't think the hydraulics is the issue as the slave and master are solid when I tested them. I put a g clamp on the slave to stop it moving and the clutch master was solid, once the piston was past the reservoir port.

I gave up a dog leg box for a factory original 4spd box

So crunch is definitely not normal, I'll be back to my garage and make my point a bit better

Edit: I've used redline mtl on a manual 635csi to good effect, but the shift on that was never as bad as the CSL is now, I think it's more than just worn synchros
Click to expand...
 
My experience with my CS w the 4 speeed is exactly as Honolulu’s and Mal’s. If I go slow into reverse no crunch. Going into 1st first seems to prevent it altogether. I have no issues at with up shifting and down shifting at any speed and running Redline of the viscosity specified in the manual.
 
Thanks for your experiences. The slow and steady approach sounds about right, I've not tried putting it in 1st first, so will try that for sure.

I have an update, which is the master cylinder is in fact duff. Bad news in one way, but good in that if something's not right then I like to have something to fix. I hadn't noticed this until looking at things from the pedal end today. If I press the clutch in slowly, which you never would in real life to be fair, pedal goes (slowly) straight to the floor. So the seal has failed, fluid coming out by pedals etc. A reasonably cheap part, so will replace and test the hydraulics again.

I found a measurement in an E12 Haynes manual, slave cylinder actuator is suppposed to move 20mm. Slightly different clutch mech, but I'll measure it anyway

And something else I read was the spigot bearing can get sticky if the car is not driven so much, certainly the case for my E9 (unfortunately) and winter is not going to help

But I'll give MTL a go before taking the box out of course, be mad not to! Something to help the synchros
 
Thinking about it, going into 1st when stationary effectively uses the 1st synchro to stop any rotation of the input shaft, meaning a move to reverse can be made with everything still in the gearbox, so no crunch. Makes sense
 
When I converted from AT to 4-spd then to 5-spd, I used the clutch master and slave from the original donor, an '80 E12 528i. That was a dozen years or more ago and I've never looked back. Plus, they were "free" with the trans. Me likey free!
 
one small thing to look out for, with the early round slave cylinders as used on 2002, E3, early E9, early E12 etc. there are two different bores, a smaller bore would give a longer throw but a harder pedal, 2002 used a smaller bore, E9 larger, not sure about the others, they look about the same externally, I won't tell how I know this............. Pat
 
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