722.1xx help in W116 needed - Page 14 - PeachParts Mercedes-Benz Forum

alfa 75 · #**196** 11-13-2007, 10:18 AM

I'd check for the simpler stuff first. Does putting the gearfshift in drive actually put the car in drive?

If yes, look at the converter. You mentioned you weren't sure how to install it. Get instructions from somebody here, take it out and install it the proper way.

If no, start looking at the linkage.

rs899 · #**197** 11-13-2007, 10:34 AM

Dunl-

I think you know the deal about the sheared TC fingers, right?

Pull a trans line hose at the radiator and see if it pumps...

Rick

dunl · #**198** 11-13-2007, 11:27 AM

Quote:

Originally Posted by rs899

Dunl-

I think you know the deal about the sheared TC fingers, right?

Pull a trans line hose at the radiator and see if it pumps...

Rick

Okay guys, thanks for the tips.

If it does pump from the trans line.....do I assume that means the torque converter is working?

rs899 · #**199** 11-13-2007, 12:51 PM

I would think that is a logical conclusion ( although there is a small rear pump on these). To be scientifc , you need to read pressure.

Rick

dunl · #**200** 11-13-2007, 02:42 PM

Quote:

To be scientifc , you need to read pressure.

From the way it was shooting out all over the floor last time - didn't think a scientific reading was required.

dunl · #**201** 11-13-2007, 09:54 PM

Well, nothing from the cooler hose at all. Not even dripping once the engine was turned on.

So the torque converter must not be seated properly, or fried. As the old transmission shot fluid out everwhere from that hose, I do know that the torque converter there should be decent.

rs899 · #**202** 11-14-2007, 07:23 AM

No pressure=Torque converter and/or front pump is likely knackerd. I can't imagine how one could assemble the thing incorrectly and just not have it work- unless one forgot all the TC to flexplate bolts and then I would think there would be a noise as the TC spins in the crankhole.

I assume the TC had good fingers when it went in? Did you trial spin it with it seated in the front pump?

You are going to get very adept at transmission removal.....

Rick

dunl · #**203** 11-14-2007, 10:25 AM

Quote:

Originally Posted by rs899

No pressure=Torque converter and/or front pump is likely knackerd. I can't imagine how one could assemble the thing incorrectly and just not have it work- unless one forgot all the TC to flexplate bolts and then I would think there would be a noise as the TC spins in the crankhole.

Well, same thoughts here. How exactly does the torque converter go on the shaft? It was already on the replacement tranny, wouldn't come off with the rubber knob on the inside blocking the way, seemed to click twice back in place, spun freely, etc. As for the torque converter bolts, they were easy.....5 minutes at most to take out and put back in.

Quote:

I assume the TC had good fingers when it went in? Did you trial spin it with it seated in the front pump?

What exactly am I looking for when checking the torque converter? Because the old tranny shot fluid out quite fine when I disconnected the hose....so either the pump on this one is shot, or the torque converter wasn't seated. Maybe I have to Frankenstein a tranny from the two.....

Quote:

You are going to get very adept at transmission removal.....
Rick

No kidding. I'm sure I can tell you what size bolt anything is from here at my desk.

rs899 · #**204** 11-14-2007, 12:32 PM

The TC on the 722.1xx has two rather slender and delicate fingers that slide into the slots in the front pump. The driven end of the TC (that faces the pump)-picture a pipe that has been cut down such that two tabs about .75 inch high and about that wide are all that remain. This drives the pump, and has a nasty habit of fatiguing and failing. IMO, there is just not enough meat on this design. If you look down at the "circle" of the "pipe", perhaps 90 or 120 degrees of the circle is left. On the later 722.3xx trannys, the fingers are much stouter, perhaps 200+ degrees remain. This will make sense when you open it up. When you do this swap, you may want to replace the bronze bushing that the TC rides on , as well as the seals involved.

Rick

dunl · #**205** 11-17-2007, 11:04 PM

Well, thank you all so much for all your help with the removal and replacement of the tranny in my 1980 300sd. I finished replacing it last weekend, only to find that the vehicle wouldn't move. Suggestions were possible linkage in the valve body which I had previously had out, broken fingers on the torque converter, or an unseated torque converter.

Well....turned out to be none of those, but simply a forgetful novice mechanic. I pulled the pan tonight, and before dropping it, I could hear something in it - NOT GOOD!

Dropped the pan to find 4 - COUNT `EM, F-O-U-R - valve body bolts in the pan!

When I put the valve body on the tranny initially, I put the bolts in finger tight. Next day, I came out and put the pan on - but forgot to torque up those bolts!

Torqued them up, reinstalled the pan, filled her up, and took her for a short drive. The clip that hold the shifter linkage has come off, and needs to be replaced I think, but other than that, she seems to be working fine.

I could thank everyone personally who has helped me with this, but there's a million posts and too many members to count. I won't single anyone out because if I forget someone, then that wouldn't be fair either.

So please, if you think you may have helped me in any short and small way with any suggestion, or know for a fact that you did, thank you so much for taking the time to help me out. I still think in all my years of the internet that this is one of my favorite forums, and it's simply because of the calibre of membership here.

I'll post next the entire list of threads pertaining to this, and close off those threads with a redirection here, hopefully tieing it all up in a nice little package of info for the next w116 tranny newbie.

Thanks again, and happy wrenching. I'm off for some Bushmills.

rs899 · #**206** 11-18-2007, 06:38 PM

Dunl-

Fantastic. I am glad you had a happy ending- without removing the tranny to find out what it was.

Whatever made you think to drop the pan this last time?

Rick

PS.

I really like the way you tied up all the threads. I wish everyone would post successes

(or failures

) so that we would learn WHAT WORKS.

dunl · #**207** 11-18-2007, 07:19 PM

Quote:

Originally Posted by rs899

Whatever made you think to drop the pan this last time?

When I had previously switched the valve bodies hoping I wouldn't have to pull the tranny, I didn't link up the gear selecting rod inside the valve body the first time. So I had to go under, pull the pan, and then reconnect that in order to find out that yes, the tranny was indeed "hooped" (Canadian word, we invented basketball, remember?

)

Quote:

I really like the way you tied up all the threads. I wish everyone would post successes

(or failures

) so that we would learn WHAT WORKS.

I'm a teacher, so it seemed logical to get it all together. Also, having all those threads out there made it hard for ME to follow.

dunl · #**208** 11-18-2007, 07:25 PM

Oh yeah....guess I get to dissect the old valve body now if I wish.

dunl · #**209** 11-18-2007, 11:39 PM

Quote:

I really like the way you tied up all the threads. I wish everyone would post successes (or failures) so that we would learn WHAT WORKS.

Please ignore that. It's all been lumped into one huge 14 page thread now.

dunl · #**210** 12-09-2007, 06:17 PM

Well, haven't had a lot of time to drive the car yet, but it seems to take a LONG time to drop into drive, and requires a huge drop off of the accelerator until it drops into gear.

I've searched for reasons for this, but I can't seem to find anything related to this. Otherwise, the tranny seems to be fine, possibly slipping into second too soo, unless the 1980 300SD's were supposed to start in second (then it would be late, I guess).