'91 300D trans stuck in 1st gear... - Page 2 - PeachParts Mercedes-Benz Forum

Stretch · #16 11-20-2011, 05:15 AM

ATSG manual states the following for "no up shifts"

Check regulating pressure. If no regulating pressure remove and clean / replace governor.

With regulating pressure remove and clean / replace shift valve housing.

MercFan · #17 11-20-2011, 09:07 AM

Quote:

Originally Posted by Army

ATSG manual states the following for "no up shifts"

Check regulating pressure. If no regulating pressure remove and clean / replace governor.

With regulating pressure remove and clean / replace shift valve housing.

THanks Army. Two questions:
1) I know there is a diagnostics port on that trans (somewhere) - that can be used to test the regulating pressure. NOt sure what to use to test it.

2) Where do I get the ATSG manual? UPDATE: never mind, found one on ebay - thx

THx,
James

JamesDean · #18 08-05-2012, 12:05 PM

Quote:

Originally Posted by MercFan

THanks Army. Two questions:
1) I know there is a diagnostics port on that trans (somewhere) - that can be used to test the regulating pressure. NOt sure what to use to test it.

2) Where do I get the ATSG manual? UPDATE: never mind, found one on ebay - thx

THx,
James

Hey James,

Did you guys ever resolve this? I seem to be going through a similar thing with my 300D 2.5

Stretch · #19 08-05-2012, 01:26 PM

Drat I'm normally a bit better at following up on this sort of stuff - sorry about that James

Did you get it sorted in the end?

pmckechnie · #20 08-05-2012, 01:31 PM

JamesDean,
When I bought my 91 300D 2.5 I got it cheap because it would not shift out of first gear. Called a friend of mine (transmission man) to get a price to rebuild. He ask what was wrong with it, I told him it would not shift out of 1st gear. He said to pull the governor out and you will find the problem. Sure enough I pulled the governor and found 1/2 of the plastic drive gear but not the other 1/2. Got a new gear from the dealer for less than $3, Installed it and trans has been fine since (about 5 years). Never found the lost 1/2 of the gear. It is still in the trans somewhere but I have been unable to find it.
This job can be done without trans removal. Governor is on left rear of the transmission. Just remove the rear mount and lower rear of trans as much as possible and push to the passenger side as far as you can. I used a tie-down strap to hole the trans to the passenger side.

Paul

JamesDean · #21 08-05-2012, 01:54 PM

Quote:

Originally Posted by pmckechnie

JamesDean,
When I bought my 91 300D 2.5 I got it cheap because it would not shift out of first gear. Called a friend of mine (transmission man) to get a price to rebuild. He ask what was wrong with it, I told him it would not shift out of 1st gear. He said to pull the governor out and you will find the problem. Sure enough I pulled the governor and found 1/2 of the plastic drive gear but not the other 1/2. Got a new gear from the dealer for less than $3, Installed it and trans has been fine since (about 5 years). Never found the lost 1/2 of the gear. It is still in the trans somewhere but I have been unable to find it.
This job can be done without trans removal. Governor is on left rear of the transmission. Just remove the rear mount and lower rear of trans as much as possible and push to the passenger side as far as you can. I used a tie-down strap to hole the trans to the passenger side.

Paul

Thanks Paul! This is immensely helpful! I'm going to verify that the kickdown solenoid is not stuck by sending 12V to it and having my buddy grab a hold of it, seeing if he feels it actuate. If he does not either 1) it stuck down or 2) its just not possible to feel.. If he does.. than nothing is wrong with it and it might be the governor.

Was it pretty easy to remove? I've never removed a governor before.. Does the fluid have to be drained? B2 piston was a PAIN on my 126..

Here's the EPC exploded view of the governor..could you point out the part that was bad on yours?

EDIT: Kickdown Solenoid seems OK.

pmckechnie · #22 08-05-2012, 03:34 PM

I believe it was #160. The only problem is a snap ring that I don't see on the picture. It would be considered part of the governor assembly. Remove #185 and #175. #180 is an o-ring around the cover #175. Now look behind the governor weights and you will see a snap ring that you must squeeze the little ears together (i think) or maybe spread them apart and hold them as you pull the governor out of the transmission. The gear is on the other end of the governor. I don't remember what holds it on but i'm sure you see what it is. If the gear is ok then look inside the trans and look at the gear that drives the gov. It could be bad I guess. Next make sure the governor works freely and doesn't stick as the weights move in and out. They move a valve inside the shaft that could be sticking. You should be able to feel something if it is sticking. Clean it Very Very good and reinstall.

I'm sorry I can't give better directions, but I did this +/- 5 years ago and I don't remember as well as I did some years ago.

Paul

JamesDean · #23 08-05-2012, 09:34 PM

Quote:

Originally Posted by pmckechnie

I believe it was #160. The only problem is a snap ring that I don't see on the picture. It would be considered part of the governor assembly. Remove #185 and #175. #180 is an o-ring around the cover #175. Now look behind the governor weights and you will see a snap ring that you must squeeze the little ears together (i think) or maybe spread them apart and hold them as you pull the governor out of the transmission. The gear is on the other end of the governor. I don't remember what holds it on but i'm sure you see what it is. If the gear is ok then look inside the trans and look at the gear that drives the gov. It could be bad I guess. Next make sure the governor works freely and doesn't stick as the weights move in and out. They move a valve inside the shaft that could be sticking. You should be able to feel something if it is sticking. Clean it Very Very good and reinstall.

I'm sorry I can't give better directions, but I did this +/- 5 years ago and I don't remember as well as I did some years ago.

Paul

Thank you kindly for this. I was reading in a Mercedes document how to remove the governor and it did not seem very difficult. It also seemed that I did not have to drain the fluid to check it.

The ATSG document said that I should check pressures at this one test port and that would tell me if the governor is doing its job. I will have to build a test gauge for that. I recall reading somewhere that its a banjo style bolt and a 250 psi ranged gauge. Hopefully I can source those or maybe I'll see if my mechanic would do it. That way I'll know if its the gov or not.

If anyone has any info on the appropriate banjo sides,etc that would be much appreciated.

Stumbled across this in AllData, looks like a promising path. AllData also reported 2.4 hours for removing the governor.

pmckechnie · #24 08-06-2012, 09:14 AM

We need a transmission tech to jump in here. I don't think our '91 transmissions have a secondary pump. My 84 500 has one but I think they dropped them just after that. I did drop the bottom cover when I did mine because I wanted to service it and wanted to find the missing part of the gear. There was nothing in the pan. 1/2 of the gear is still MIA. I think the instructions you found apply to the older trans but #1 and #6 still apply.
I'm sorry I forgot to say that you will only loose a small amount of fluid when you take the governor out. They say to replace the gear on the output shaft. That is what would make the labor so high. That would require that the drive shaft and output housing would need to come out. All I can say is I didn't go that far and have had no problems.

Paul

JamesDean · #25 08-06-2012, 09:29 AM

Quote:

Originally Posted by pmckechnie

We need a transmission tech to jump in here. I don't think our '91 transmissions have a secondary pump. My 84 500 has one but I think they dropped them just after that. I did drop the bottom cover when I did mine because I wanted to service it and wanted to find the missing part of the gear. There was nothing in the pan. 1/2 of the gear is still MIA. I think the instructions you found apply to the older trans but #1 and #6 still apply.
I'm sorry I forgot to say that you will only loose a small amount of fluid when you take the governor out. They say to replace the gear on the output shaft. That is what would make the labor so high. That would require that the drive shaft and output housing would need to come out. All I can say is I didn't go that far and have had no problems.

Paul

I dont think we have secondary pumps either. I believe they stopped in 1990. Wasn't the secondary pump, in part, for pop-starting the car? We did that on my buddy's 90 300SE once. fun time.

The ATSG pdf says to remove the output shaft and all that jazz. The Mercedes 722.3 pdf says to just remove the gov. Looks like a few easy-ish steps.

JamesDean · #26 08-06-2012, 12:33 PM

I think I'm just gonna go ahead and order the gear from XXXX. I've gottta order some 6-pin headlight adapters anyway.

Is there any other parts I should order? A seal or something?

pmckechnie · #27 08-06-2012, 03:51 PM

O-Ring for the cover.
Paul

JamesDean · #28 08-06-2012, 05:52 PM

Quote:

Originally Posted by pmckechnie

O-Ring for the cover.
Paul

Parts Ordered. $25+shipping later. Probably didnt need a few of them but figured why not..

JamesDean · #29 08-10-2012, 01:00 PM

Well today is the day.. I'm gonna lift up the front half of the car, drop the belly pan, drop the rear end of the transmission and hopefully pop off that governor cover and see whats up..

The books all said to clean the governor...what do i clean it with?

Stretch · #30 08-10-2012, 02:58 PM

I'd use brake cleaner for the part you can remove from the transmission and then let it dry. I would not use anything other than clean transmission fluid to clean the hole from where it came. ATF is actually quite good at cleaning, though the problem you might have is reaching difficult corners. Ear sticks might help - but don't leave any foreign objects in there.