PeachParts Mercedes-Benz Forum - View Single Post

JHZR2 · #1 12-19-2003, 02:10 PM

Hi,

My ATF was last replaced by an independent shop, and it has alwyas been at the right level, but there are tiny fittle bubbles on the dipstick. Fearing aeration might be reducing the quality of the fluid (I dont know what brand was used, but it was put in by an MB only shop), I figured Id take it to the deale to be changed.

I got in, and when he saw my car, he was very hesitant. He asked me if Ive ever done ti before, all the typical stuff that people will ask when dealing with an older high mileage car, so the trans doesnt die as soon as the fluid is changed.

I told him that in the last 50k since I got the car, Id had it done twice, and the trans is still fine. He said OK, and went to have it done, as well as look at the vac modulator to check, because at cold startup, the shifts are either slow or real hard. (I figured theyd want to sell me some service so I ought to have them diagnose it). He also then told me that trans fluid should only be changed every 60k in general in these old cars, because changing it too often will loosten up too much dirt and then it wont shift right and may slip completely. I like 24-36k, personally...

Eventually they came back and said that the fluid looked clean, so I shouldnt change it. They also told me that I needed to change the 'piggyback' vacuum valves (P/N 002 997 53 36) which are the vacuum valves on the valve cover that control the trans shifting. They siad they were worn almost all the way. They would replace them to the tune of $325.

The also told me that the caster blocks (P/N 123 330 13 35), aka guide rod mounts were bad. They would change them for a cost of $560.

I know that my front end makes a knocking sound every time that my wheel is turned far to the right or left. Used to do it once each way, now it does it twice. also hear a clunk when I abruptly let on or off the throttle when driving slowly. Would that be because of the guide rod mounts?

Would worn vacuum valves effect cold shifting, but allow 100% fine shifts when warm?

Unless there is something tricky about the changing of the trans valves, I will do that myself. They are $36 at fastlane and should be ab easy job.

I have read that the guide rod mounts are reaql tough to do on the 300D, because you have to remove the spring. That is not something I want to tackle.
Is there any way that the guide rod mounts can be done by a driveway mechanic without screwing around with the springs? Most likely Ill have the indy do that though...

Any info on these things would be great.
Thanks,

JMH