Hi Kids,
Have just purchased an 89 F150 with 59,230 original miles. It had 43,890 miles on it in 92 and has been driven only in summers to tow a boat since. Great shape. Think it has some ring and pinion issues. It has a clunk in the drive line. Thought it was a universal but they are fine. No sound or feel when put in drive or reverse. Shifts are quiet and smooth when accelerating. The clunk occurs when gentle gas applied and the trans shifts or when cruising at freeway speed and I get quickly off then on the accelerator. Feels and sounds like a universal or trans mount but again, they are fine. Someone locally said Ford had a lot of trouble with the 8.8 rears( which is what I have). Anyone have any,"rear," experience with these?
All The Best,
Bill

 

Welcome to FTE!

There is nothing wrong with the 8.8" rear diff. look in my gallery at what I put mine through every weekend. Have the 'back lash' (ring to pinion distance) checked an have new bearings installed. Unless they are worn down a lot, that should fix it.

It could also be an engine or transmission mount.

 

Thanks for the info. Say, that's looks alot like my driveway in winter!

Bill

 

Is it a 4x4? if so could be slack in the transfer case. Is there any noise from the rear when driving? I had a sort of whining noise in my 93's 8.8" and turned out to be that the pinion ended up getting pushed into the axle housing an over a several thousand miles, it had ground out about a 1/4" from the axle's housing. The noise was noticeable under loads or when decelerating, but got worse and worse until it did it all the time. Then one day the floor started shaking as i was cruising at about 45mph and pulled over to find that the rear end was toast. I had someone change the tranny from drive to reverse while holding the brake. I watched the driveshaft at the diff turn almost 3/4 a turn and the yoke would move in and out of the axles about 2" I ended up taking the shaft off and ran the truck in 4wd (converted it to a FWD truck temporarily) until I got the parts to fix it. The rear axle was entirely coated with metal filings inside. All the seals were shot, and the pinion bearings were torn to pieces. After cleaning up the mess I installed a new ring and pinion set and a limited slip diff from a 2003 cobra mustang which I got off of ebay all brand new for $300. Bearings and seal set cost about $180 at a local drivetrain shop. Did all the work in about 20 hours straight. I flushed the oil several times after that to make sure any loose filings were removed. I've put on another 50,000 miles since then and it is still nice and tight.

I guess the moral of the story is that all the noises you hear are telling you something, and it might take some hunting to find out what it is, or just wait till it breaks like i did! The bronco now has 273,000 miles on it, which is quite a bit more than your 89. I would have someone shift the tranny between forward and reverse and take a look at the entire drive line underneath and look for a play and listen for noises. You may not hear it from inside unless there is a large load, but it may be more noticeable up close. Just make sure they keep their foot on the brake.

 

Thanks also. It's a 2x4 and other than the occasional clunk it's really quiet. Like the idea of having someone else inside while I check from the underside. I'll give it a try and post the results.

All The Best,
Bill

 

Hi and Welcome,
Crawl under and check the tranny mount, likes to loosen.

Cheers,
Popa Tim

 

I have a 1992 4x4 and I had the same noise. I changed the tranny mount and it was still there. After about a year of trouble shooting I discovered it was axle wrap. The leaf springs were shot allowing the axle to over torque. I put new leaf springs on it and no more clunk. My dad used it for years to haul farm equip. and tractors. Just a thought.

 

It may just be the torque converter...