I'm in the process of doing an engine swap and was working on dropping the transmission and t-case last night. I pulled the rear drive shaft off and the rear pinion flange is really loose. The shaft and nut didn't seem to be wobbling at all, just the flange. (i've never driven the truck, i bought it with a bad engine) the truck has 160,000 miles. Just wondering what to do. Should i try to tighten the pinion nut? Does this sound like a bad pinion bearing? Any input would be greatly appreciated. Thanks in advance.

 

does it move up down or in and out?

 

It wobbles. So i guess it would have to have some in and out play for it to wobble around the shaft. right?

 

The nut move with it? or does it stay in place? Might be a pinion bearing, I have seen several 8.8s with blown pinion bearings around that mileage.

 

Neither the nut nor the shaft wobble. Just the flange.

 

Does the diff cover show signs it has been off recently ie- semi-clean bolt heads,blue form-a-gasket squeezed out around edges ?
Someone may have had it apart to "repair" it and done a shoddy job.

 

I'll take a look for inidcations of recent repair work. I know the previous owner had the clutch and slave cylinder replaced a year or two ago right before he ran the engine out of oil and i found indications of that work.....loose crossmember bolts, loose shifter boot, etc.

 

I've got a wrecked 2003 edge sitting out in the pasture. I think i might take the rear end out of it, throw it under my truck so i can put some miles on the junkyard engine during it's 90 warranty, then i'll completely go through the fx4 rear end while its out from under the truck. I definately don't want to run the rear end as is and risk damging anything, and i need to get the truck on the road asap. I'll look at it again tonight, as i'm running on memory here at work. Thanks for the input.

 

I'm back at home now and looked at the pinion flange again. it does not move in or out or up or down. It has rotational free play. it can spin 1/4 to 1/2 an inch. Is the pinion shaft splined where flange connects to it? How does this work and what could cause it to rotate like that?

 

I'm an idiot. The pinion nut was just loose. I turned it half a turn and it tightened the flange up. i'm gonna pull it off and replace the seal though. Thanks for all the help.

 

Rotational play is not abnormal. The gears just have a small amount of play between the drive and coast sides of the gear. You could have thrown off the tolerances of the gear set if you tightened the pinion nut enough to eliminate that play in there and that could lead to bigger problems with the bearings or the gear set itself.

 

I barely had to turn the pinion nut, it was pretty loose. After i tightened it there is about the same play i've felt on other rangers. It had just worked it's way loose.

 

A friend of mine with a 2002 FX4 had this same issue not to long ago. Weird.