Gear box going south? Rough in downshifting...

[Olivier]

I have posted this before, just wonder if someone might have a wee knowledge on it again, I changed the engine and gear box mount as it was time and I was hoping it would solve some of the roughness of the gear box.
Thanks to Franey for the mount , good price and fast delivery.
About the box, when the car decelerate and go down to about 20 miles it downshift but not really smoothly ( to second I guess), sometimes harder then other time?
Down to about 5 miles it downshift to first gear simili, a wee hard, not smooth changeover, like a manual car when you let the clutch goes too fast.
When I apply the brake to finally stop the beast, there is a kind of wheel/ momentum still spinning trying to push the car forward more then it should, like a little hiccup and a kind of clung when it finally stop.

I saw somewhere but canno find it anymore that some replace the spring on the side of the gearbox, as one was broken, would those spring be the problem or is the box going south without me
Thank you.
Olivier

Just found the post about the spring, they are the 722.6 Pressure regulator spring
to be find there:
722.6 Pressure regulator spring replacement - Benzworld.org - Mercedes-Benz Discussion Forum
would that be the problem? Is the 722.6 same gearbox as mine?

 

[Will]

Might be worth checking the condition of the propshaft couplings and for any backlash in the diff whilst you're at it?

Wil

 

[AANDYY]

Pop ya VIN. code in here and I think it tells you your gearbox type etc.
I've only used it once so I might be wrong.

Mercedes-Benz Club Russia | Mercedes-Benz / VIN

 

[Olivier]

Might be worth checking the condition of the propshaft couplings and for any backlash in the diff whilst you're at it?

Wil

I did had a look few month ago, not that long. The donuts are fine, there was a wee play on the propshaft in the middle on the UJ, but nothing major. Would that be the bother? Is the UJ in the prop repare able, or do I need a new one or its the whole prop that need to be replaced?
Thank you.

Or it could be the diff? I was loosing a bit of oil 2 days ago, its fine now, so far...

 

[Olivier]

Pop ya VIN. code in here and I think it tells you your gearbox type etc.
I've only used it once so I might be wrong.

Mercedes-Benz Club Russia | Mercedes-Benz / VIN

thanks Andy,
it says 722608 00 314913

First numbers are the same, 7226.
Is that the same?

 

[AANDYY]

I've no idea, sorry

 

[AANDYY]

I get this as well, not as much as you I think but I can feel it, it's intermitent, I just thought it was normal .
It's at a point that doesn't really concern me but would be nice if smoother, may be I'm being to picky.

 

[Olivier]

It might be normal tho? What I am looking at might just be the normality? My indie drove it last time and didn't find anything, beside a wee play sometimes but he was impress with the smoothness of the drive. Might be me, perhaps I should detach meself to the car a bit and not been in tune as much

 

[AANDYY]

Yes simular to me that, being 'in tune' with your car is a double edged sword!

 

[BlackC55]

Have you changed the gearbox oil at all?

 

[AANDYY]

I did about 10k miles ago.

 

[Olivier]

It was done last year on mine not long before I got the car, but seeing the way the car as been maintained I reckon it was a poor job. Perhaps a new oil change would be recommended.
I also found out that the plunger on the switch for the S/W was stuck on W with some sticky spillage ( trully the guy who had the car before was a moron), apparently not good for those boxes to be on W all the time, and who knows for how long the car was stuck on W???

 

[Olivier]

Got a suggestion from America, might be the electric/ conductor plate. Any imput there?
I need a shed, a lift, a star system, tools, tons of them or simply just a another car

 

[nsket]

Hi, I know this is an old post but did you solve the problem with the downshifting? I think I have the same issue.

 

[AANDYY]

I'll link him this thread for you, he doesn't appear on here as often as before.

 

[Olivier]

Cheers Andy for the link .
At the end I changed the spring and the bother was the same
Then I saw that the front rear sub-frame mounts were rotten. I changed them and all good now.
In Think as the sub-frame was wobbly it was playing havoc with the gearbox/ shaft and was also giving a little clunk.
Olivier