Drive belt adjustment nut/rod - PeachParts Mercedes-Benz Forum

erc22 · #1 11-28-2004, 08:41 PM

The drive belt adjustment rod (MB '87 190E-2.3), which has the nut threaded onto it, has either detached itself from I assume the tensioning roller or broken off from it. This is a very difficult area to get a view of how the rod is supposed to be attached. Can someone please explain what needs to be done to reattach the rod?

Thanks,

erc22

Gilly · #2 11-28-2004, 08:47 PM

What happened that it became attached? May be easier to tell you what to do.
Gilly

erc22 · #3 11-28-2004, 09:24 PM

Gilly,

If you give me your phone number I will call you.

erc22

Gilly · #4 11-28-2004, 09:34 PM

Like hell you will........

Gilly

erc22 · #5 11-28-2004, 10:10 PM

Sorry Gilly, misunderstood what you had written.

I noticed that the drive belt seemed to be loose so I tried to tighten the tension a little. I did loosen the large bolt first. When I tightened the adjustment nut it didn't seem to affect the tension and then the rod just seemed to detach itself or it was already broken or partially broken.

Thanks

Gilly · #6 11-29-2004, 05:04 AM

OH, I see where what I said could be misunderstood. Oh well, the number of times I've told someone to go to hell on the forums I can count on one finger (guess which one) Hee hee, just kiddin'.
OK, more than likely the part on the tensioner the rod clips in to broke off. There can be several reasons for this, but ultimately the reason would be because the tensioner has worn out (also this is why it didn't tighten up). There is an "L" at the end of the rod and it slips into and is clipped into a small protusion on the tensioner, the protrusion can break off if for example the nut on the rod runs out of thread (twists and breaks the protrusion) or the rod could have just popped out, but if you ran out of thread in this case, it's because the tensioner (again) is worn out, OR the tensoner itself may have hit a bolt or other obstruction on the front of the engine as you tightened it, which jammed the tensioner and again, the rod broke off this protrusion (like an "ear") that it slips in to or the rod popped out, but once again the reason the tensioner jammed up against something is because it's worn out.
So, you can try looking and seeing if the tensioner is broke or not (I'd just start taking the tensioner off, actually), but ultimately I'm really really sure you need a new tensioner, it's a common problem, not a fantastic design.
Gilly

erc22 · #7 11-29-2004, 08:23 AM

Thanks a lot for the info Gilly. I'll be working on getting a new tensioner assembly today.

erc22 · #8 11-29-2004, 02:10 PM

Heh Gilly,

Thanks again for the info. I've begun to remove the original belt tensioner assembly. There is one bolt tucked behind the power steering pulley and it appears that the pulley needs to be removed to access that bolt. Is there a trick to removing this pulley? There are 3 bolts securing it to the power steering flange and of course the pulley turns. If you have any other piece of advice regarding the removal of the tensioner it would be greatly appreciated.

Thanks,

erc22

Gilly · #9 11-29-2004, 04:16 PM

Nope, just remove the 3 bolts. You can use 2 13mm wrenches, one to counter hold and one to loosen, this will get 2 of them loose, then with the 2 bolts cranked out 5 turns or so you can use a bar (screwdriver or whatever) to counterhold while you loosen the last bolt.
It's been awhile since I removed the tensioner on a 102, don't know if I'd be of much other help, but if you have a specific question let me know.

Gilly

psfred · #10 11-29-2004, 06:59 PM

The only thing that may not be obvious is that the little plastic ring with a pointer has to be put on with the pointer at the line to the right of the "ramp" cast into the tensioner body (that is, past the "short" end).

Install tensioner and rod, pulleys, and belt. Leave 19mm main bolt just snug (the rod rotates the inner part, not the outer part and it has to move), then tighten the adjuster until the "pointer" moves to the top part of the "ramp" cast on the tensioner.

Tighten 19mm bolt to 55ft/lbs, I think.

If you have the bolt tight when you attempt to tension the belt, you will break the tensioner rod again.

Peter

erc22 · #11 12-02-2004, 12:12 AM

Gilly,

Thanks for your help. Got the pulley off and replaced the tensioner. The protrusion or ear on the tensioner was broken off. Everything working as it should.

erc22

Gilly · #12 12-02-2004, 08:47 AM

Glad you got it, and without any more questions either, you did alright!
It's not a very good design, you would think some out of work engineer with a passion for Mercedes would have come up with a spring-loaded (simple) replacement for this, they used this on several different engines and they ALL do this! Bet they'd sell a TON of them!
Gilly

psfred · #13 12-02-2004, 10:25 PM

Gilly:

It DOES work very well until the rubber goes.....

I prefer the system on the 60x diesels -- just a spring and shock, usually lasts about 200,000 miles when the shock goes and the spring snaps. 20 min fix for either one.

Peter