Torque bind slipping
Thread Starter
|
Cross-Country
Joined: Jan 2005
Posts: 83
Likes: 3
Torque bind slipping
1990 F-250 351W, M5od. I live on a steep gravel road and sometimes need 4x4 to keep from lighting up the rear. With dry conditions & 315-75 tires there isn't much slippage. I can get about 1/2 way up and it starts to bang & pop. I towed a #6000 trailer the other day and it sounded like it was going to explode. I'm surprised that it still runs but something ain't right. Where should I look first for damage? Are the hubs skipping teeth or is the transfer case (1345) lunched? All's OK in 2wd.
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
How long have you owned the truck?
For 4x4 to work smoothly all 4 tires have to be the same size and the front and rear axle gearing must also match, if you don't know the history of the truck it is possible one of the axles may have been changed and now the gearing doesn't match, that would cause binding in 4wd and eventually damage to some part of the drivetrain.
Or maybe the t-case is damaged internally, or the front diff is damaged, or one or both of the front hubs is stripped.
To figure this out you have to systematically test each part.
With the t-case in 2wd when one of the hubs is locked the corresponding drive axle should spin with the tire.
If both hubs are locked, t-case in 2wd, the front drive shaft and corresponding drive axle should spin together.
With the front hubs unlocked and t-case in 4wd the front driveshaft should spin and be solidly locked with the rear driveshaft
Does the truck have auto or manual front hubs?
Auto hubs are notoriously failure prone so you might start there after doing the above checks.
For 4x4 to work smoothly all 4 tires have to be the same size and the front and rear axle gearing must also match, if you don't know the history of the truck it is possible one of the axles may have been changed and now the gearing doesn't match, that would cause binding in 4wd and eventually damage to some part of the drivetrain.
Or maybe the t-case is damaged internally, or the front diff is damaged, or one or both of the front hubs is stripped.
To figure this out you have to systematically test each part.
With the t-case in 2wd when one of the hubs is locked the corresponding drive axle should spin with the tire.
If both hubs are locked, t-case in 2wd, the front drive shaft and corresponding drive axle should spin together.
With the front hubs unlocked and t-case in 4wd the front driveshaft should spin and be solidly locked with the rear driveshaft
Does the truck have auto or manual front hubs?
Auto hubs are notoriously failure prone so you might start there after doing the above checks.
Thread Starter
|
Cross-Country
Joined: Jan 2005
Posts: 83
Likes: 3
I've owned it for maybe 10 years. Scooter-bob owned it before me & trashed it pretty good. Ran it without oil, wiped out the synchros & gutted the cat. Anything more ambitious would have required too much effort. The tires are 315-75-16 all the way around. Way big but I got a deal. Previously running 245-75-16 and don't remember this problem. Front axle is 3.54 open & read was changed by me for a #8900 full floater 3.55 open. Hubs are manual Ford. I'll start going through the testing sequence & see what I can find. Just wondering if there's a known weak spot to look for.
Logistics Pro
Joined: Aug 2010
Posts: 3,716
Likes: 583
From: Chillicothe
the light duty f250 came with the Mazda. I had an all original 89 6600 f250 that had it.
Logistics Pro
Joined: Aug 2010
Posts: 3,716
Likes: 583
From: Chillicothe
As far as I'm aware they didnt, but I also dont think the 351 came in the LD trucks either. So, without a door sticker pic, we have to assume one or the other has been changed.
Trending Topics
Thread Starter
|
Cross-Country
Joined: Jan 2005
Posts: 83
Likes: 3
The truck originally came with a 302. When that blew I went with the 351 for more torque.
Disassembled the hubs & the engagement ring teeth were shot. EZ fix.
Disassembled the hubs & the engagement ring teeth were shot. EZ fix.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
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
Thread Starter
|
Cross-Country
Joined: Jan 2005
Posts: 83
Likes: 3
Actually with the 3.55 gears I'd rather have an auto. Sometimes I have to kick it in low range to back up to save the clutch. This trans is so bad that I changed the atf to 15-40. Synchros don't work 'till it gets warmed up but it did quiet it down. A ZF would probably be a better choice but you never see one @ the junk yard. I'm running a 4r70w on another vehicle & love it. Since this is a "farm truck" I can't justify the time & expense to change it. 351 has more torque which this sorely needs.
Thread
Thread Starter
Forum
Replies
Last Post
wfo1955
1961 - 1966 F-100 & Larger F-Series Trucks
0
Oct 29, 2016 03:20 PM