Serious hopping when in reverse

I've recently begun a restoration project on my 1971 Cj5. The jeep was garaged for 25 years... so it has/had all the usual issues i.e cracked seals yada yada. Now that I've gone through and replaced all the seals, fluids etc. and have it in good working order I still have one major issue: Everything works great until I put it in reverse and then it hops and bucks like I'm pushing over a brick wall as I release the clutch... If I release the clutch completely it moves smoothly but there are times when you need to go in reverse slowly and I cant just pop the clutch out every time I go in reverse. Ive had the frame on a rack and its straight, it has a completely new suspension system and drive train seems true... Ideas???

 

I have two of the V6 Cj's. Both do it. I have always thought it was due to the high range reverse ratio being too tall. Both have the 3.73 axles. AM

 

Got a pic of the setup?

 

oil on clutch disk........rear main or front tranny seal needs attention.

JB

 

you guys are great.... what an awesome way to share insights on a shared obsession with jeeps! here's to earlycj5.com and modern technology

 

I don't have anything like that, and my rig doesn't hop at all. Clutch is smooth, easy, and steady. I am thinking that the problem is slightly loose engine mounts, tranny mounts. If the engine moving a smidge causes the clutch linkage to change length slightly you can get REALLY weird clutch action.

-Hill

 

I have a friend who has a cj2a that used to do that. His solution was very simple. He found that the T/C mounted emergency brake was sticking (even though he didn't use it). I guess the return spring was weak or it was too gunked up and wanted to partially engage.

He never noticed this going forward, but going in reverse he had the problem all the time.

So, you might try lubricating the mechanism on the brake, and putting a big spring holding it open. Give 'er a test drive or backup, and let us know if it is any better.

 

my 67 did the same ting when i first got it... it was missing the xfer case hold down on the passenger side. someone had put a turnbuckle in instead of replaceing it so everything was free to rotate over when it wanted to. maybe check the xfer, transmission, and engine mounts too??

 

Anybody have any V6 motor mounts they want to get rid of? I'm having the same reverse chatter and just took a look at my motor mounts and they are pretty worn. At first I thought it was my installation of my AA chain conversion but it appears to be the mounts. Are there poly mounts out there that would replace the rubber ones? Or is this not a good way to go? Stick to rubber?

 

My Jeep(s) have the cable but I have never tensioned it much. Maybe I learned a new trick today. I have the service manual but have never run accross the procedure for tensioning the cable. Does anybody have a reference?

 

none of my V6 CJ's ever had one...(70 and 71)
was this an factory option?

 

My 70 had the cable but I removed it while installing the sm420 trans.
Didn't have the reverse jump problem before or after.
I would check motor mounts and transfer case side mount.

 

I worked on an early Bronco many years ago with the same problem.The thing would shake so bad in reverse, I thought the windshield would pop out. It was missing the front body mount bolts. Only took about two hours to find the problem LOL.

 

Actually I have installed the two motor mounts one on each side and the third back by the tranny... hopping occured before and now after as well. Is there another tranny mount(s)? I'm not sure if I have the tension cable or not and I cant look at my jeep right now in that it is in the body shop getting a new set of clothes. The Body mounts are being replaced and two spacers are going to be put in place of those pathetic sheet metal spacers that collapsed years ago... I'm pretty excited about checking into all your suggestions.... keep them coming! You guys are great!

RavensRude