300cd 82, slipping in fourth - PeachParts Mercedes-Benz Forum

t walgamuth · #1 02-11-2006, 08:13 PM

my indie reported the tranny shot. today i drove it and here is what i found. first and second seem solid. there is a vac leak it seems so that may be contributing. it will shift into and hold third fine but when it shifts into fourth it slips and slips. pull it back into s and it is fine.

i had thought third and fourth were completely gone so i figured that band was broken but it seems it just is not locking down properyly.

any thoughts?

tom w

t walgamuth · #2 02-12-2006, 10:35 AM

i know there are fellows out there who understand all those little parts in the automatic tranny!

tom w

pawoSD · #3 02-12-2006, 06:52 PM

Fluid? Filter? I know mine does some of those things with low fluid....and it shifted better in general with synthetic fluid and a new filter....

C32AMG · #4 02-12-2006, 07:57 PM

The K1 and K2 clutch drums are applied for 4th gear. If you feel no slippage and holding 3rd gear,
No slippage in reverse once it’s fully engaged, we can rule out burnt friction in the K1 and K2 drums.

Possibilities: Since B2 release oil is part of K1 and K2 feed oil, there can be a leak in the B2 circuit;
Or a problem in the valve body.

t walgamuth · #5 02-12-2006, 09:34 PM

and get back.

i seem to remember a discussion recently as to whether a 240 auto will work in the 300. but cant be sure what was said.

thanks for the info and help.

tom w

t walgamuth · #6 04-26-2006, 09:58 PM

ok i am back on this problem.

it slips in fourth. reverse does not. i changed the fluid and filter again. this time i did the torque converter too. the filter was black. i have a k-1 spring kit but no instructions and it doesnt look like the pics that have been posted, so i put it all back together and drove it around manually shifting it around to see if i could get some cleansing action.

now i noted when it was all off that three of the bolts on the valve body were different, like hardware bolts, so perhaps someone has had the vavle body off and there is a problem there.

any smart ideas?

tom w

Pete Burton · #7 04-27-2006, 08:44 AM

Three bolts are of slightly longer length, they are on the right-most side. I didn't know that you could check the K2 with reverse engagement, but if C32AMG says it, you can take it to the bank. He was very helpful to me last summer when I rebuilt my 722.303. I do know that a black filter is NFG

Better keep your eyes peeled for a good used trans.

t walgamuth · #8 04-27-2006, 08:47 AM

yeah, this one is probably toast. i have been diddling around with it just in case.

if it doesnt respond to cpr i have a four speed to install. stick.

tom w

TwitchKitty · #9 04-27-2006, 11:12 AM

Quote:

Originally Posted by t walgamuth

yeah, this one is probably toast. i have been diddling around with it just in case.

if it doesnt respond to cpr i have a four speed to install. stick.

tom w

Coupe with a manual four-speed sounds great if you are set-up to do the work.

You really need a transmission manual to troubleshoot this thing. There is a step by step flowchart for each transmission in the professional manuals, ATSG, Mitchell, or MB. I have never done a MB tranny but on other trannies that I have studied up on I would be looking for either low pressure in the circuit or an eroded friction surface. Pressure could be a valving problem, pump or a leak, gotta hook-up gauges to tell.

t walgamuth · #10 04-27-2006, 02:07 PM

yeah, well i am not set up for that,... for sure.

so i am going to try one more thing and then prob punt.

tom w

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