1978 FJ40 Shutters...only in Reverse. Any ideas? (1 Viewer)

[allesad]

Looking for any ideas on how to best diagnose this issue.

Background: Recent Barn find 42K Miles Original. It barely ran as a back it out the driveway, hit the brakes and the rear drums locked up, I gassed it and skidded the rear wheel 15', then drove fwd into garage. Time for teardown and repairs. It's now been 4 months after a complete flush/fill/lube/belts/plugs/brakes/carb/desmog/OME/33's, .....I back it out of the garage for a shake down drive and the rear drive line studders hard and loud. Drive Fwd into the garage....she drives smooth.

The u-joists are lube and look good, I remove the driveline , torque the pinion flange and its OK. Decide to keep the rear drive line off. Lock the Hubs, go to H4 and back it out of the driveway ...same problem...noise is in the Tranny/TC area.

Next Step, Check Motor mounts..., they are semi rotted in the rear and loose....so I "washer them up" and torque them down.

Back it out....same problem.

IDEAS???
THX


Any ideas

 

[CRZR45]

Sticky clutch disc ? Maybe needs the surface cleaned? Moisture rusted the clutch disc and surface possibly.

 

[allesad]

Great idea, will check it. The FJ was stuck in a river for a day or two, then pulled out, dryed out and drove to and stored in a barn in 1984. So a sticky clutch is possible.

I keep thinking the issue is the Tranny or TC.
My FJ buddies tell these can take alot of HP/Torque, they where surprised on any issue with them.

I have also, loosed the E-Brake, think it may cause the shudder/wobble. Will open it up and look inside as well.

 

[allesad]

The official term is "Judder". Seems to happen on old rusty flywheels and clutch plates. THX CRZR45 great idea. I learned that slipping the clutch in 2nd or 3rd will eventually clean it up...and it did!! Took about 30 minutes of slip driving and it smooth now.

On to the next issue.

 

[JohnnyFish]

I have the same issue occasionally on my ‘79 and I assume it’s the drum emergency brake. Haven’t made the time to look into it yet.

 

[airon23]

Great idea, will check it. The FJ was stuck in a river for a day or two, then pulled out, dryed out and drove to and stored in a barn in 1984. So a sticky clutch is possible.

I keep thinking the issue is the Tranny or TC.
My FJ buddies tell these can take alot of HP/Torque, they where surprised on any issue with them.

I have also, loosed the E-Brake, think it may cause the shudder/wobble. Will open it up and look inside as well.

I have the same issue occasionally on my ‘79 and I assume it’s the drum emergency brake. Haven’t made the time to look into it yet.

This I suspect is the answer. Recently I rebuilt the E-brake but never calibrated it for a few months. When I finally did set it, I felt like I tested it well enough driving forward/backwards and so I let it alone. I started using it when I remembered just to make sure and soon noticed the clunking sounds you're talking about when I'd go in reverse. And then driving forward would correct the issue until the next time.
It became enough of a nuisance that I eventually readjusted the brake pull out handle to so that when pressed all the way back in it now doesn't hang up like before.

Good luck

 

[65swb45]

Update?

Add me to the list that thinks it’s the E brake.

 

[NHFJ]

Looking for any ideas on how to best diagnose this issue.

Background: Recent Barn find 42K Miles Original. It barely ran as a back it out the driveway, hit the brakes and the rear drums locked up, I gassed it and skidded the rear wheel 15', then drove fwd into garage. Time for teardown and repairs. It's now been 4 months after a complete flush/fill/lube/belts/plugs/brakes/carb/desmog/OME/33's, .....I back it out of the garage for a shake down drive and the rear drive line studders hard and loud. Drive Fwd into the garage....she drives smooth.

The u-joists are lube and look good, I remove the driveline , torque the pinion flange and its OK. Decide to keep the rear drive line off. Lock the Hubs, go to H4 and back it out of the driveway ...same problem...noise is in the Tranny/TC area.

Next Step, Check Motor mounts..., they are semi rotted in the rear and loose....so I "washer them up" and torque them down.

Back it out....same problem.

IDEAS???
THX


Any ideas

punch it