Shuddering on reverse only

[jogirob]

Hello all, there's this strange quirk that I noticed when going in reverse. It feels like the transmission or driveshaft is shuddering. Shuddering strength increases the more gas I give it while going on reverse. It's not terrible but noticeable. All forward gears are smooth as butter and engage nicely at the proper shift points. Just barely swapped in a rebuilt A904(A999) about 800 miles ago.

What do you guys think it could be?

 

[Johnpat]

Might be a right side mount problem.
Torque transfers to opposite side in reverse

 

[Fran Blacker]

Broken trans mount or engine mount?

 

[jogirob]

I installed a new transmission mount just before the old trans went kaput. I'll be sure to double check my torques on it though. I'll take a look at the right side mount, all those engine mounts are still the originals with 228XXX miles I believe. Thanks all.

 

[Don Frelier]

Just an idea:
Have you looked inside the rear brake drums?
You could have a leaking seal, gummy pads that are loose.
When you back up the shoes grab and rock.

 

[jogirob]

Just an idea:
Have you looked inside the rear brake drums?
You could have a leaking seal, gummy pads that are loose.
When you back up the shoes grab and rock.

Hmm this would be quick to factor out by lifting the rear on jacks and manually spinning the tires. I'll try that out thanks Don!

 

[Don Frelier]

I would still recommend pulling a drum on each side.
Look for leaking wheel cylinder, rear seal, check pad condition and adjustment.
Old drums always have a wear/rust lip on the inside towards the inner edge.
You can take an angle grinder and remove that lip even give it a slight chamfer so the pad does not touch there.
Adjust rear pads out until you can just get the drum back on.
Hopefully nothing is leaking in there, but with that many miles anything is possible.

 

[66 Sat]

Mine was doing the same thing, most noticable going slighly uphill in reverse while turning (getting back in the garage). Perfect going forward. I asked a friend and he suggested the reverse band?? might be glazed and wasn't gripping properly (I think this is what he said). He suggested putting some anti-shudder in the box, reckons the auto transmission shops use heaps of it. Anyway, I bought a little tube of the stuff and it worked. Shudder has gone away.

 

[jogirob]

Mine was doing the same thing, most noticable going slighly uphill in reverse while turning (getting back in the garage). Perfect going forward. I asked a friend and he suggested the reverse band?? might be glazed and wasn't gripping properly (I think this is what he said). He suggested putting some anti-shudder in the box, reckons the auto transmission shops use heaps of it. Anyway, I bought a little tube of the stuff and it worked. Shudder has gone away.

I live on a fairly busy street and the only way for me to get up and into my driveway without scraping is if I reverse into it. As I quickly get into position to start my reverse maneuvre it always seemed a little extra stubborn but I assumed it was from fighting against the wheels turned to the max. This is where the shudder is the worse. If I'm not mistaken though the low/reverse band are the same thing in these A904's. Why would it not do that on 1st gear? Anyways some anti-shudder additive is easy enough to give it a shot.

 

[jogirob]

So I was thinking about the rear brakes possibility and it would make total sense. I put on a lot of pressure right before reversing into my driveway. Things are probably getting hung up. I slightly pressed on the brake pedal while backing up and the shuddering goes away. I'll keep you guys posted.

*update* I popped open my rear drums and the right drum had a chunk of metal bouncing around. I think it was part of a brake shoe. Brakes needed a lot of adjustment at the star gear also. I sprayed the entire thing down with brake cleaner and sanded the glaze off the drum. Seems to have fixed it.

 

[miller]

had a chunk of metal bouncing around

Hmmm...wonder where that chunk of metal come from...food for thought.

Just discovered a leaking axle seal, on my 8 3/4". Somebody out there passing out hexes???

 

[Don Frelier]

So I was thinking about the rear brakes possibility and it would make total sense. I put on a lot of pressure right before reversing into my driveway. Things are probably getting hung up. I slightly pressed on the brake pedal while backing up and the shuddering goes away. I'll keep you guys posted.

*update* I popped open my rear drums and the right drum had a chunk of metal bouncing around. I think it was part of a brake shoe. Brakes needed a lot of adjustment at the star gear also. I sprayed the entire thing down with brake cleaner and sanded the glaze off the drum. Seems to have fixed it.

Glad you got it figured out. Now concerning my bill...