No reverse. Tranny or diff?
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Freshman User
Joined: May 2005
Posts: 38
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From: Perry, Utah
No reverse. Tranny or diff?
I just towed 9k lbs 2500 miles and noticed last night during my stop that the reverse was jerking and grabbing while trying to park. All forward gears work flawlessly but reverse is now bad enough that I had to put it in 4Low to get my trailer backed into my driveway.
Some facts for you guys to help me out:
99 F250 7.3L 4r100 180k miles.
Some facts for you guys to help me out:
- Tranny temps never got above 205 the whole trip and averaged 165-180.
- I do not get a blinking OD light.
- During my trip I sheared off all 8 lug studs on my right rear wheel and lost the tire wheel. This was half way in my trip and it worked flawlessly after the repairs were made to the rotor/brakes/parking brake/backing plate, etc (long story in another thread here)
- Earlier yesterday decending Tioga pass my brakes got a bit warm so I stopped half way down. When I let them cool and got going again I had it in 1st but it must have automatically popped out because when I noticed I was doing 40mph with low RPM. I put it in 2nd and it grabbed and helped slow me down. I noticed my tranny temps shot up to 180 very fast after that.
- Tranny fluid is full, just changed before our trip, and doesnt smell burned.
99 F250 7.3L 4r100 180k miles.
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Freshman User
Joined: May 2005
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From: Perry, Utah
Dumb question here, but wouldnt the diff work in forward AND reverse not one or the other (excuse my lack of knowledge here). Also, I had my diff serviced before I left. If they didnt add the friction modifier for the limited slip would that cause a massive failure? I noticed it was grabbing on tight turns in forward both before and after the diff fluid was changed (I belive 75w140 synthetic was used...whatever is called for).
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Freshman User
Joined: May 2005
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From: Perry, Utah
We never could find a real solution to the studs shearing off. I-80 west of Sacramento is VERY, VERY rough and I think the studs may have already been weakened by me not using a torque wrench when I rotate my tires. I always just crank them down and I could have stressed them by doing that. Combine weak studs with harsh bumps and that is about the only reason I can think of the studs shearing off. The lug nuts didnt fall off as there wasnt any evidence of movement on the stud holes in the wheel.
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Joined: Mar 2007
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From: Dunwoody, GA
Originally Posted by sglynx1
Transmission problem. No possible way for the diff to fail in reverse but work in forward.
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Freshman User
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From: Perry, Utah
No, just into camp spots and if its on an uphill incline I'll throw it in 4wd or 4 low to let the gearing help out.
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From: Stephensville WI
Originally Posted by sglynx1
Transmission problem. No possible way for the diff to fail in reverse but work in forward.
I've had a differential act up going reverse but not forward. The pinion nut had worked loose. The torque applied to the pinion moving forward was enough to keep the pinion gear more-or-less in place, but when backing the pinion gear would move away from the ring gear, creating all sorts of binding and grinding noises and making the entire rear axle assembly kind of do this odd hop/squirm thing.
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Joined: Mar 2007
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From: San Jose , ca
Reverse issue
Originally Posted by riggz
hmm. well def. sounds like transmission. take it to some place that offers free diagnostics and have them check it out.
Problem is the only way to check the one way thingy is by disassembly. Most trans shops will want to do that and then advise on repairs, mostly they recommend a complete replacement with a rebuilt unit.
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Freshman User
Joined: May 2005
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From: Perry, Utah
It grabbed and jerked then slipped then grabbed and jerked then slipped....Engine rpm's had to be up higher than normal for it to move too. I'm thinking its the tranny from what everybody says. More than likely burned up the clutch when I had it in M1.
I've got an appointment at my local dealer to install the new HD4r100 this Friday. They are also going to pull the rear differential cover to to a quick check inside before they do the tranny just to make sure its not the problem.
I know everybody recommends John Wood or BTS but this upgraded heavy duty Motorcraft reman looks pretty good and they gave me a decent parts and install price but the nice thing is that they can have it done later this week.
I've got an appointment at my local dealer to install the new HD4r100 this Friday. They are also going to pull the rear differential cover to to a quick check inside before they do the tranny just to make sure its not the problem.
I know everybody recommends John Wood or BTS but this upgraded heavy duty Motorcraft reman looks pretty good and they gave me a decent parts and install price but the nice thing is that they can have it done later this week.
