R129 500 SL Gearbox and Selector Lever Issue!

Hi All, I have a 1991 R129 500SL, it has just reached 70,000 miles, the problem is a combination of things (maybe cause by one) the first issue is when I first start the car and select "D" and and start to drive off the car seems to stay in 3rd gear and never moves up or down a gear even if i press the pedal to the floor! if I use the gear lever and select the gears manually they work, right down to selecting "2b" so now I have to drive my car and change gears manually, my next problem is that once I get going I then cannot select "R" Reverse or "P" Park as the selector lever will not allow me to select these modes, the gear selector lever just will not pass "D" no matter how hard I try, the only way for me to select "R" or "P" is to switch of the engine and take out the keys out from the ignition barrel, wait a couple of seconds then select "P" start the engine then select "R" Reverse, so as you can see its a pain in the A... to park especially when ther are cars behind you and you need to parallell park!!!

 

I would have said that adjustment of the selector rods and cables would fix this. I may have some details on how to do this

 

Hi All, I took my 500SL to my local inde to check out my problem previously mentioned, I have noticed that the gearbox appears to be in LHM (Limp Home Mode) which means it remains in 3rd gear from start but it will change up/down using the gear shift lever except for Reverse or Park unless I switch of the engine which allows the lever to move in to Reverse or Park, when I went to it to the inde I realised that if the ignition was left on without the engine running the lever can be moved so the inde said that the problem seems to be in the gearbox so I had the gearbox oil and filter changed hoping that it may rectify the problem bit it did not, he explained that it seems to be a hydraulics issue which would mean that the gearbox will need to come out!
I cant beleive it as I only had the gearbox rebuilt 4 years ago and have only covered 15'000 miles since then, does this seem right.
at first I thought it may be a faulty selector gate but the gate opens freely when the engine is not running.

 

It could be the link cable from the ignition switch not working properly - you know, the one that prevents you taking out the ignition key unless the car is in Park.

 

This is a hard one,,I can let you have the complete linkage set up

 

linkage set up

Hey Television

It's been a while since you mentioned it, but can I get the linkage set up doc? I'm pretty sure my problem is a linkage adjustment as I can get it to go into 4th if I move the lever to the right and part way up into N.

TIA

Waynesb

 

gearbox!

HI, is this a four speed hydraulic box or 5 speed electronic . i thought this early it would be hydraulic in which case limp home etc wouldnt apply and it would be mechanical . linkage . etc.

 

I will need an Email address and the next 3 numbers after 129

 

linkage adjustment procedure

Hi Malcom

My car is an R129058, a '94 SL280. I've PM'd my email address.

Thanks for your help...

W

 

The above is not the case.

There is transmission overload protection built into the older hydraulic gearbox, and can cause the EZL/AKR control unit to switch to emergency operating mode to protect the gearbox.

This hydraulic pressure switch provides transmission overload protection for gears 1, 2 and 3.

A clue can be found if there is a misfire at high speed with engine over 3000 revs.

The overload switch S65 and wiring should be checked.