Lost 5th gear and kickdown

[30260]

A local specialist changed the gearbox oil and filter in my 320sl. This has worked wonders on the low gears but I now find that I have lost 5th gear and have no kickdown. Specialist says it is a coincidence, but I know problems started after oil change. They have had the car now for nearly a week and have failed to find the cause.
Has anyone had a similar problem or can anyone shed light on this problem.

 

[television]

A local specialist changed the gearbox oil and filter in my 320sl. This has worked wonders on the low gears but I now find that I have lost 5th gear and have no kickdown. Specialist says it is a coincidence, but I know problems started after oil change. They have had the car now for nearly a week and have failed to find the cause.
Has anyone had a similar problem or can anyone shed light on this problem.

What are the next 3 numbers after 129 on your VIN.

Malcolm

 

[30260]

Next three numbers are 063.

 

[television]

Next three numbers are 063.

OK will look it up tomorrow, im off to bed.

Malcolm

 

[cyps]

air flow sensor ?

 

[television]

OK you have the 722.6 gearbox, there are no listed faults for no 5th gear.

You can check by driving at 62 mph level ground, move selector to 3rd approx = 4500 rpm. 4th = 3150 rpm and D = 5th 2300 rpm.

Malcolm

 

[30260]

Specialist tells me the 5th gear clutch is burned out and gearbox needs rebuilt and ecu must also be replaced. This seems a sudden problem from a gearbox which was ok 100 miles ago before oil and filter change !!!

 

[flagstaff]

aye - very strange. i had a similar problem not so long back, same gearbox. lost fifth gear on a long drive, and kickdown also. the cruise control stopped working at the same time. next day it all came back again. go figure. my guess is that it's something electrical or vacuum related. electrical because fifth gear on these gearboxes is electronically controlled, and vacuum because that among other things has a hand in the kickdown process. what about the kickdown relay? just throwing out thoughts here - you need to give the car to someone who knows what they're doing. if you say what area you're in, someone on here will be able to point you to a competent specialist indie.

 

[television]

Something not quite right here, The kickdown is electric,switch under pedal.
this leads to the gearbox ETC The 4-5 shift is an electric solinoid, and its the same one that does the 1-2 shift so cant be that.

I have run out of time, there will be fault codes recorded, I cant see it being possible to burn out 5th gear, the slightest touch on throtle or incline it drops back to 4.

I think your gearbox guy is a S..T, I will come back tomorrow.

Malcolm

 

[30260]

I think I need a second opinion ! Can anyone suggest a merc or gearbox specialist in the Glasgow area ?

 

[C220GJS]

Try here; Brian Melville (MB specialist) Vehicle Engineering ;based in Busby (nr Glasgow, Scotland) on 0141 644 4190 for all aspects of MB work.
Or; T.J.O'Neill (Independent MB Specialist);Unit3, 33 Camelon St, Carntyne Industrial Estate, Carntyne, Glasgow, G32.6AF. Tel. 0141 778 5314.

 

[30260]

Another post suggests that this box is prone to leaking oil into the ECU through the rear seal. Anyone concur?

 

[television]

Another post suggests that this box is prone to leaking oil into the ECU through the rear seal. Anyone concur?

Not on the 722.6 box, even if it did it would cause your fault. oil does not effect the ECU other than to contaminate long term. Any one with that problem could have it washed and resealed for £20.

Malcolm