Rear diff is binding, rear end pops off ground?
Thread Starter
|
New User
Joined: Jul 2010
Posts: 4
Likes: 0
Rear diff is binding, rear end pops off ground?
I have a 1974 F100...
When I put the truck into reverse, it seems to bind up bad...takes so much torque to break it loose that the rear end pops off the ground a bit. It's making some horrible groaning and grinding sounds in reverse too. I'm certain the transmission isn't the issue because the sound is coming from the rear of the truck. I bought the truck pretty recently...and didn't look closely, but the fill hole on the diff must have been welded shut by the previous owner. It's welded, so I can't take the case off and have a look. Here's a pic so you can see what I mean...
If anyone has any ideas as to what I should do here...truck has been sitting in my driveway for a week now and I'm getting antsy and sick of riding the bus...lol thanks for your help!
When I put the truck into reverse, it seems to bind up bad...takes so much torque to break it loose that the rear end pops off the ground a bit. It's making some horrible groaning and grinding sounds in reverse too. I'm certain the transmission isn't the issue because the sound is coming from the rear of the truck. I bought the truck pretty recently...and didn't look closely, but the fill hole on the diff must have been welded shut by the previous owner. It's welded, so I can't take the case off and have a look. Here's a pic so you can see what I mean...
If anyone has any ideas as to what I should do here...truck has been sitting in my driveway for a week now and I'm getting antsy and sick of riding the bus...lol thanks for your help!
Post Fiend
Joined: Dec 2007
Posts: 8,521
Likes: 16
From: Lost
That diff "cover" was welded on by ford. That's a 9" rearend, and the gearset comes out the front of the housing. Also, the fill plug is on the front, between the driveshaft and axle tube, usually on the driver side.
I'd be willing to bet you need the diff rebuilt. Sounds like pinion bearings have given up the ghost, at a minimum.
I'd be willing to bet you need the diff rebuilt. Sounds like pinion bearings have given up the ghost, at a minimum.
Post Fiend
Joined: Dec 2007
Posts: 8,521
Likes: 16
From: Lost
Ummm, wow. Sounds like it's time to drop the 3rd member, and go salvage yard hunting.
If they welded the fill hole, there's no telling what else is inside that diff., but I'd bet it ain't pretty......
I'd drop it to determine which spline axles you have, and look for a replacement. That, or hunt for a complete rearend to swap. Your's is toasted. And buttered.
If they welded the fill hole, there's no telling what else is inside that diff., but I'd bet it ain't pretty......
I'd drop it to determine which spline axles you have, and look for a replacement. That, or hunt for a complete rearend to swap. Your's is toasted. And buttered.
Thread Starter
|
New User
Joined: Jul 2010
Posts: 4
Likes: 0
That's what I'm guessing too, haha. Only problem now is that I've been to five or six salvage yards...and they all have F100's, but every last one of them has been stripped bare. The only one I've seen that even still had the rear diff, it was obviously toasted and buttered worse than mine is, haha...
Post Fiend
Joined: Dec 2007
Posts: 8,521
Likes: 16
From: Lost
That's why I suggested dropping out the center and seeing what spline your axles are. The 9" was used in many cars and trucks from the 60's to the mid 80's. Many different ratios were used, as well as u-joints, but there were only 2 factory spline counts. 28 and 31. Find the right spline, in a useable gear ratio, and it's easy to swap the pinion yoke to make a 3rd member from any other year/type vehicle work in your truck.
That's the beauty of the 9". The entire unit comes out the front, so it's relatively easy to swap the gears out.
That's the beauty of the 9". The entire unit comes out the front, so it's relatively easy to swap the gears out.
Hotshot
Joined: Oct 2002
Posts: 18,488
Likes: 22
From: The Big, Oregon
The 9" was used up to 83 in F100s, F150s, and vans, but the vans and later F100s typically had a high ratio.
Trending Topics
Lead Driver
Joined: Mar 2004
Posts: 8,922
Likes: 153
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
Thread
Thread Starter
Forum
Replies
Last Post
