Rolls-Royce and Bentley Forums banner

1 - 10 of 10 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter · #1 ·
The car was shifting just fine. I parked at a restaurant and when I finished eating and got back to my car, I shifted out of first and into reverse. When I went to shift into first the shift lever wouldn't go back to first. It would only move forward and back. Letting out the clutch, the car was still in reverse. Looking at the service manual, it refers to "an incorrect setting of the bronze reverse actuating lever" and how to adjust it by rotating the eccentric pivot pin. Does any of this sound familiar? Any ideas? Any help would be appreciated!
 

·
Registered
Joined
·
485 Posts
I just repaired a worn synchro cone on mine, so I have become quite familiar with that transmission, you may want to post this over the Australian forum.

Australian RR Forums: The Infamous MK VI Transmission Thrust Washer

Adjusting the bronze actuating lever with eccentric pin is there so the gear teeth of reverse mesh properly into the second and third motion shaft, adjusting that would only affect that, but would not change where the shift lever position is and getting it in and out of reverse.

What I think has gone wrong is that the shift lever gate is not aligning with the shifting rods well enough to allow the transmission to come out of reverse. Mine was the same way, but I adjusted the shift gate on the frame of the car to align with the shifting rods of the transmission instead. I took a piece of hard wood and created a wedge to do the job.

There is a rod out the back of the transmission that allows the whole engine and trans. to move forward or backwards to allow proper alignment to the shifting gate.
The rod is rubber mounted, and the rubbers perish with oil, this allows the movement of the transmission and engine, which in turn throws the gate alignment out with the shifting rods of the transmission.

The other thing that causes this problem are the engine mounts them selves, the rear mount is especially susceptible to failure from oil contamination, the front mount, not so much, it's high up and out of oil contamination, but if it's been in there for some 70 years, it may be perished as well.
Also remember that the torque rubbers at the back of the trans as well, if the rod is adjusted to get it to shift properly, then the mounts for the torque rubbers have to be re-shimmed.

Here's a screen shot of where the adjustment is.
Keep in mind that there is only so much adjustment because you're working against the exhaust when the trans/engine is moved forward or aft.

I would start with the rear transmission mount and make sure it has not allowed it to settle before any adjusting is done.
If you remove the floor, it makes it much easier to work on.

Trans..JPG
 

·
Registered
Joined
·
485 Posts
There will be a point where it will work properly and then not, what I mentioned is the way to adjust and deal with your problem.
If it was my car, I would start with the inspection of the rear transmission mount and then move on to the Gearbox tie rod rubbers and then the torque rubber mounting.
If you don't know the history of the car, then you may want to replace them without inspection, they may have been in there for decades and are at a critical state.
Or if you bought the car where the seller said that all this was taken care of, and in fact it wasn't, but given the fact that you can't get it out of reverse the mounts have moved enough, and they have to be dealt with right now.
You may find that the tie rod rubbers are totally gone and replacing them will cure the problem, but some adjustment may be needed after replacement.
It's a wonder the whole thing works as well as it does, since the shift gate is a totally separate entity bolted onto the frame apart from the transmission; where the transmission and engine assembly is rubber mounted and allowed to move around under the torque of the engine when driving.


Mounting Rubbers (introcar.co.uk)

If you find one that's gone bad, then it may be a good idea just to replace them all, they're not that expensive.
If you start adjusting the engine to get it to shift properly on old mounts, it will just move again.

You can jury-rig it by moving the shifting gate where it's bolted onto the frame by elongating the holes, but that would not be a good idea, or like I did and make up a wedge like shim underneath the shift gate to match the shifting rod positioning in the transmission.

At any rate, removing the floor to carry out the repair does make the job quite easy, but if the floor has never been touched, it may be best to do it from underneath.
There's some 40 1/4 inch machine screws to undue to get it out.

Circled in red is where the shift gate mounts, and arrowed in orange is where the torque rubbers go.
I had a bad oil leak at the back of the engine on the camshaft cover, this required the removal of the transmission to get at it.
I'm still in the process of cleaning and painting while I have it apart, mine was quite the evil mess in there and I can't stand working on a dirty area.

Do you have a place to work, do you like to get your hands dirty ?

If not, the problem is finding someone who knows what they're doing.

Bentley Floor.JPG
 

·
Registered
Joined
·
485 Posts
All this assumes that the transmission is healthy of course, but having totally taken my transmission apart, there is nothing really in there that would cause it not to get out out of reverse with in itself, but I suppose anything is possible.

The adjustment of the eccentric pin is to get the correct clearance of the reverse motion shaft against its thrust washer.
Adjusting that would only affect that, not the smooth shifting out of reverse and into first.

When in neutral, the shifting rods in the transmission all line up and have no adjustment.
The rods have to match the action of the shifting gate and the way to adjust that is to move the whole engine/trans assembly for. and aft.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #6 ·
Again, thanks for the info. I have a nice, big garage to work in. Have been thinking of dismantling the whole thing and doing my own complete restore...
 

·
Registered
Joined
·
485 Posts
I re-read your post again, thinking something has gone wrong with the gate itself that won't allow you to get it out of the reverse plane and into the 1st/Second plane.
Anyways, something else to think about.
My shifting gate was very dirty and full of oxidized grease that defeated the shifting lever from freely moving sideways.
Sometimes I had to start in high gear.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #8 ·
The shift lever only goes a couple of inches forward and a couple of inches rearward with no resistance. I'll check the gate and the other spots you mentioned.
 

·
Registered
Joined
·
485 Posts
Before going and checking all the mounts, there is an access panel underneath that hides where the shifter bolts onto the sliding mechanism that goes into the transmission.
The panel is near the shifter in the car, but underneath.
Remove the panel and shine a light up there and see if the four small bolts and nuts are tight.
Note that the triangle shaped panel may be missing.
 
1 - 10 of 10 Posts
Top