'91 300D trans stuck in 1st gear... - Page 5 - PeachParts Mercedes-Benz Forum

Zulfiqar · #61 08-22-2012, 01:02 PM

^^ I changed out the rear seal on my car - and used a brass punch to unstake the nut and then used a northerntool socket to undo the nut with trans in park.

Didnt dig deeper, but the parts most probably are self explantory when the tail cover is removed.

Stretch · #62 08-22-2012, 02:40 PM

I've put some pictures of a 722.303 in bits here

722.303 in bits photo shoot

They might help.

JamesDean · #63 08-22-2012, 03:43 PM

Yes! I saw this. It was very helpful.

When removing the parking gear and pin setup.. How difficult was that?

Stretch · #64 08-22-2012, 05:31 PM

Very easy.

(But then the transmission was out the car - I was standing upright - I had a cup of coffee just out of shot!)

JamesDean · #65 08-22-2012, 08:59 PM

I got the tailshaft off in short order. Had the old drive gear removed and the new one replaced in under a half hour. I've just installed the governor. Now its just a matter of closing everything back up. Then I'll drop the pan, change the filter and gasket and refill it.

I'm debating on whether or not I want to re-attach everything (driveshaft/exhaust/etc) and then try out the transmisson OR secure the tail of the transmission and start the car as it sits on the stands and see if it shifts.

I'll probably call it quits for the night after I close up the tailshaft and governor bore though.

Here's some pics for your viewing pleasure. I did find the broken piece of the plastic gearing. It was sitting in the back of the tailshaft cover.

So tonight's progress:

-Governor Installed. Confirmed to be spinning with movement of output shaft.
-Governor bore seal, cover and snap ring installed.
-Replacement drive shaft plastic gear, tailshaft seal, and cover installed.

I have this fear that the parking gear is just going to move around in there and disconnect from the governor. It wasn't clear to me what held that in place. I saw what looked like a spacer/sleeve.

I have it installed plastic gear - snap ring - sleeve - parking gear. I hope that is correct. I recall the sleeve coming out AFTER I removed the parking gear and not before. So that makes me think it is right.

Tomorrow:
-Replace pan gasket, filter.
-Torque tailshaft bolts, install output flange and torque 30mm bolt.

I'm thinking about filling the trans back up, bolting it back in place and starting the 602 up, putting it in drive and seeing if it shifts before re-attaching the exhaust and driveshaft. I'd rather not have to go through disconnecting all that **** again if something goes tits up. Any thoughts on this? Bad idea? good?

Friday is 190 rear shocks and steering damper day!

homepagz · #66 08-22-2012, 09:11 PM

Boy does this look familiar. I was just where you're at a week ago with my '92 300D 2.5. Once I replaced the plastic gears and fixed the issue with the secondary pump it is shifting like a dream now.

-John

pmckechnie · #67 08-23-2012, 09:20 AM

Starting up before connecting drive shaft is a good idea. However, DON'T put transmission back into park before turning off the engine. The tail shaft will still turn even in neutral with the engine running. There is a safety feature that keeps the shifter from going into reverse while the car is moving forward above a certain speed but it can still be moving some and it wouldn't be good to stop the transmission that quick when it goes into park.
From what you have seen, do you recommend I remove the tail housing just to get the broken gear out of my trans, or do you think it will be ok to leave it in there? It has been in there since Jan 2005. I didn't realize I had this car for 7 1/2 years. Time flies when you are having a good time.

Paul

JamesDean · #68 08-23-2012, 09:51 AM

Quote:

Originally Posted by pmckechnie

Starting up before connecting drive shaft is a good idea. However, DON'T put transmission back into park before turning off the engine. The tail shaft will still turn even in neutral with the engine running. There is a safety feature that keeps the shifter from going into reverse while the car is moving forward above a certain speed but it can still be moving some and it wouldn't be good to stop the transmission that quick when it goes into park.
From what you have seen, do you recommend I remove the tail housing just to get the broken gear out of my trans, or do you think it will be ok to leave it in there? It has been in there since Jan 2005. I didn't realize I had this car for 7 1/2 years. Time flies when you are having a good time.

Paul

Good tips. I'll be sure to follow them. I plan on doing this when I get home today from work. Gotta see how much ATF I'll need. I just drained the pan yesterday, not gonna touch the torque converter.

You know from the looks of it, I can't really see to many paths for it to return to the oil pan as long as its a a big piece still. Now if it should somehow be turned into smaller pieces..I think there would be some pretty bad things that could happen. A small piece could be moved around to the point where it gets in between those plastic gears.....

I think if its a large piece then you're probably OK as you've been for the past years. But smaller, easier to move pieces...might not be so much...

diesel friend · #69 08-23-2012, 03:29 PM

for sure, appreciate very much sharing all the details with us. It seems when
these transmissions get older, the helical gear should be changed. Wondering
whether anybody knows what a transmission shop would charge for a replace-
ment. Would be too much work for me.

JamesDean · #70 08-23-2012, 03:53 PM

Seems like it largely depends on your locale.

Near me, I asked the one transmission shop about rebuilding my 722.303 on my SD. They said $3k. They said they don't actually do it, they just buy and install.

I doubt they would have tackled the governor issue. When I ordered my parts from XXXX, Mercedes-Benz of Naperville, IL called me to tell me some of the parts had to come from Germany. They seemed to know what I was doing though. So you might be better off at the stealership.

JamesDean · #71 08-23-2012, 09:32 PM

Today's Work:

When I got home from work I was fairly tired so today's accomplishment are somewhat limited.

I torqued all the tailshaft cover bolts in place and installed the output flange with a new nut and torqued that down.

I'd like the collectives thought on this idea:

I was going to drop the pan, and change the filter and gasket however, it occurred to me that I might just want to fill it up. If my repair is successful (and hopefully it is) then after a few hundred miles I would take the car in for a transmission service and have it drained and changed. That would allow any (if any exist) contaminants from the outside being open to get into the filter and pan.

Anyone have any thought on that? Or Should I just drop the pan, change out, fill up and go?

compress ignite · #72 08-24-2012, 01:05 AM

Changing out the ATF in the T.C. and Tranny body with a new filter would be
a preventative "Just in Case" something else slid down there that you're not
aware of YET.

I'd CLEAN the exterior of the Tranny FIRST and change it out myself!
After all the TLC lavished on your tranny...
the Wrenches @ Jiffy Lube or the Dealer would not be trusted.

JamesDean · #73 08-24-2012, 08:14 AM

Quote:

Originally Posted by compress ignite

Changing out the ATF in the T.C. and Tranny body with a new filter would be
a preventative "Just in Case" something else slid down there that you're not
aware of YET.

I'd CLEAN the exterior of the Tranny FIRST and change it out myself!
After all the TLC lavished on your tranny...
the Wrenches @ Jiffy Lube or the Dealer would not be trusted.

Hmm. So would you do it now, or in a few hundred miles?

I would most certainly not take it to a place like a Jiffy Lube or dealer! It would pay a visit to my trusted import only mechanic that the family has been going to since '82.

Given my past success rate with AT pan/gaskets, which is hovering in the 50% area. (2x green 300SD, 2x gold 300SD, 1x 420sel (oil pan)) I was just going to say hell with it. Give it to them, they can also double check my torque on the flex discs and other prop shaft things.

Which leads me to another question. Should I do anything with my center carrier bearing and associated rubber?

The bearing didnt seem bad to me.. Nor did I have any noise complaints prior to the AT going down.

A Coreteco support is $50 and a Timken bearing is $17 I think.

Zulfiqar · #74 08-24-2012, 02:29 PM

If the support and bearing are good leave them be, just make sure that you smear some moly paste on the splines and also a teaspoon of the same paste in each bushing cavity on either side of the shaft.

This paste/grease is best had from motorcycle repair shops who service shaft drive motorcycles like Honda VFRs or any BMW 2 wheel. Its the stuff they use when the wheel is mounted to the hub.

You can also look for some very high moly content grease (CVJ) - I think napa sells it.

Stretch · #75 08-24-2012, 02:32 PM

Quote:

Originally Posted by JamesDean

...
Given my past success rate with AT pan/gaskets, which is hovering in the 50% area. (2x green 300SD, 2x gold 300SD, 1x 420sel (oil pan)) I was just going to say hell with it. Give it to them, they can also double check my torque on the flex discs and other prop shaft things.
...

What's gone wrong with a transmission pan and a gasket?

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