Reverse Adjustment Band - PeachParts Mercedes-Benz Forum

sknaffl · #1 05-09-2009, 01:28 PM

I picked up the new '80 300sd yesterday and have been tinkering around with the no reverse problem. The PO said the band was broken and not out of adjustment...I questioned that since I could feel the car trying to reverse.

I pulled the adjustment bolt and the pin/plunger out..cleaned everything up and tried to reassemble.... I can now screw the adjustment screw all the way in with almost no resistance....so...I'm wondering...

Does the pin at the end of the screw have to be aligned...or should it just line up when you start tightening down the adjustment bolt? How would you align it with the tranny in place...can you access it with the pan off?

Or...could the reverse band really be broken and there is nothing for it to tighten down to?

I'm prepared to pull the transmission if necessary...but really don't want to...I'm hoping this is going to be a simple fix....any ideas?

#2 05-09-2009, 04:20 PM

How do the rest of the gears work? I'm pretty sure a broken reverse band should affect 1st gear too. Put the shifter in L and see what it does.

sknaffl · #3 05-09-2009, 05:00 PM

The rest of the gears are fine...shifts great 1-4

sknaffl · #4 05-09-2009, 06:25 PM

so...I screwed the adjustment bolt in as far as I could without worrying about room for the locknut...when I tried reverse...it actually engaged..but then I heard a loud scary POP..and the engine died.

I immediately pulled the adjustment bolt back out...pulled out the pin...everything looked fine. I reassembled and left the pin out to it's original position....started up the engine again and everything sounded ok

I have no idea what the pop could have been....I seem to have less resistance when I try and screw the bolt in...so who knows.

rs899 · #5 05-10-2009, 06:32 AM

On the 722.1xx transmissions, IIRC there is a very clear view of the band with the valve body removed (unlike the 722.3s). If it were me and I was committed to pulling the tranny anyway, I would drop the pan and the valve body and try to see what's going on. If it's the band, you will have to take it out. Could possibly be the strut that holds the band is broken (small chance). Sounds like you are in for a bit of a fix.

Rick

sknaffl · #6 05-10-2009, 07:31 AM

Quote:

Originally Posted by rs899

Could possibly be the strut that holds the band is broken (small chance). Sounds like you are in for a bit of a fix.

Rick

Is the strut replaceable with the trans in situ? I'm preparing for the worst here...which is fine...I figured on worst case scenario when I bought the car.

I feel comfortable in pulling the trans, but I've never really dug around inside an auto transmission before...how difficult of a job is the reverse band for a novice? If I decided to pull the trans and take it to a shop for a complete rebuild how much should I count on paying?

rs899 · #7 05-10-2009, 09:24 PM

Quote:

Is the strut replaceable with the trans in situ?

I think it may be so, on this one.

Quote:

but I've never really dug around inside an auto transmission before...how difficult of a job is the reverse band for a novice?

There's a first time for everything. The reverse band on this one is fairly easy, IIRC. Basically pull the front end of the tranny off with the front pump, and there it is....

A "complete" shop rebuild.... $1000+ maybe

Rick

sknaffl · #8 05-10-2009, 10:34 PM

Quote:

Originally Posted by rs899

I think it may be so, on this one.

There's a first time for everything. The reverse band on this one is fairly easy, IIRC. Basically pull the front end of the tranny off with the front pump, and there it is....

A "complete" shop rebuild.... $1000+ maybe

Rick

Well...I guess I know what I'll be doing the next couple of evenings...At least I will be able to see what's going on with the pan off. I picked up a filter kit today at my local Auto Zone and it looks completely different then what I have...he said the six bolt was all that was showing for my model...but I have the 4 bolt design on the pan.

I can't wait for it to be fixed....I've been detailing it most of the day...cleaning out all the years of gunk....and it really amazes me how great of shape the car is in...barely a ding anywhere and just a couple of rock chips in the paint. The engine sounds sooooo smooth....oh yeah..and the interior...wow...I know..I'm bragging.....can't help it.

The only thing that really bugs me are the wheels...which are in desperate need of refurbing...or maybe switching out with some nice hub caps...not to mention the old couple the owned it put the white walls out!!

sknaffl · #9 05-16-2009, 11:54 AM

Well I guess there is no adjustment for this. This is what I found when I pulled off the pan and valve body. The seat for the strut was just floating around and pretty much just fell out. The rest of the band is intact, it was a clean break so I don't think I have any shards of medal floating around.

Any suggestions for where to purchase this band? I don't see one listed on Fastlane, and I have searched the internet for internal MB transmission parts with no luck.

Also...has anyone ever used the transmission jack from Harbor Freight...the one that fits on your floor jack? I was thinking about buying this one today with hopes of getting the transmission out of the car today while I'm motivated.

Simpler=Better · #10 05-16-2009, 12:30 PM

If the rest of the transmission runs fine I would just park in places than you can pull through.

Harbor freight tools are hit or miss; but they usually hold up for at least one usage

Matt L · #11 05-16-2009, 12:46 PM

If it fits on your existing floor jack, there may be little enough to it that it will last through several jobs.

sknaffl · #12 05-16-2009, 01:00 PM

Quote:

Originally Posted by Matt L

If it fits on your existing floor jack, there may be little enough to it that it will last through several jobs.

I think I'm going to go ahead and pick it up...I might have to do some slight modification to get it to fit my jack...but I've read some other threads where people have used it and it seems to be ok...

I'm hoping this is a one man job..since I doubt I can convince any of my friends to get covered in transmission fluid today.

I think the reverse band may be a MB dealer part...none of my usual sources have it nor can get it.

badgator · #13 05-16-2009, 01:22 PM

I used my large HF 3 ton? floor jack, drilled 4 holes on saddle, and bolted a piece 2"x8" 16"? long, to it and a couple drywall screws on top so the tranny wouldn't slide off.

This was on a Volvo 960 rwd but I used it on a FWD minivan + others too. Cutting wood is cheap, easy, fast.

Just be sure the weight is centered / balanced !!!

I can make a custom board / plate in less than 15 minutes, just have to figure
out the trans center of gravity.

If you haven't r+r plenty of trans before buy the HF TJ and use the security strap if it comes with it !!!

sknaffl · #14 05-16-2009, 08:52 PM

Well...I can definitely say...don't waste your money on the Harbor Freight tranny adapter that goes on your floor jack. You have to get the vehicle ridiculously high to get the tranny out....luckily I realized this before I got it all dirty and I will take it back tomorrow.

I'm going to go for the $89 scissor jack...or the $129 hydrolic jack they have...or maybe Northern has one.

Either way...it's better than the $850 I was quoted just to remove and reinstall the tranny from my local indy....and that's with me still repairing the reverse band.

rs899 · #15 05-17-2009, 09:21 AM

Yeah- the HF tranny jack is useless for anything but a truck or SUV, IMO. On the 722.1xx you can pull off the bellhousing once you wrestle it to the ground, if you wish, making it the lift lower. I used 2 jacks, one front and back. It did it by myself, so you should be able to, too.

To remove, you might try to find 2 or 3 nesting cardboard boxes to drop the tranny on. Then cut away the boxes sequentially, crushing the last one.

Try jie.com for the band (and advice)

Good luck.

Rick