Center Support Bearing (Drive Shaft)

[snicklas]

Here is who I plan on using...... not sure if they can get them for others........

http://www.ficmrepair.com/index.cfm...ct_id=351/category_id=-1/mode=prod/prd351.htm

 

[tbrumm]

Body shim kit could be your friend here just to play around if your bolts are long enough. I'm not sure but the 350 may have a longer center support mount.

Nope, I just measured the center support bearing drop bracket in my 94 F350 CCLB and it is only 3" tall.

 

[laserjock]

Huh.

 

[catbird7]

Ideal candidate would be a factory built F350 extended cab 4x4 with 8' bed. Curious is center support bracket is greater than 5". Going home early today, so I'll be test driving tonight with .400" shim.

 

[laserjock]

True. I missed the crew cab part.

 

[The Bus]

This may or may not help. I did not see any mention of this type of check.

Years ago I had trouble with a carrier bearing on a '68 Chev C10 - the old rear coil spring config. The old one went out and I purchased a replacement and installed it (indexing the drive shaft pieces and endpoints).

Took it out and it was OK at first. After awhile it started vibrating again and eventually the vibration was horrible. A friend who was an old school mechanic told me to put it gear without the motor running (auto - in park no motor running).

While laying on the side of the truck (not under the bed), watch the drive line while someone else pushes/pulls on the truck. You looking for drive line movement. Just like you would be looking for a bad U Joint.

If the drive line moves in or out and/or up and down at all your drive line is not secured at the axle. If the axle/drive shaft is secure, you'll see the drive shaft turn and stop. If not, you'll see the axle force the drive shaft out of alignment. Movement will prematurely wear out the bushing/force it out of spec and cause wobble/vibration in the drive line.

My issue was with a bushing/shim on the axle. It was so minor that I never would have saw the movement until I watched the drive shaft movement. A new carrier bearing and some bushing work and it was smooth as silk.

Axle alignment/movement can cause a lot of issues if gone undetected.

I hope this helps.

 

[bbjordan]

Old Guys Rule!

an old school mechanic

The depth of knowledge/experience on this site continues to amaze me!

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[catbird7]

Thanks for the reply's and I'll def perform the above mentioned "check". Here's what I learned over the weekend. Drove truck to MD again (another 220mile round trip). This time with .400" spacer under carrier, this produced no noticeable improvement, zero, nothing! I also took an infrared "lazer pointer style" thermometer. Drove truck approximately 40 miles and pulled off into a large vacant parking lot and crawled under and started taking temps. Air temp was 49 degrees, U-joints on front drive shaft were 70 degrees, U-joints on rear drive shaft were 85 degrees, rearend near pinion and tail shaft of transfer case were both 125 degrees. I've never taken these temps before therefore have nothing for comparison however none seem out of ordinary. I sit in the cab and listen & listen and all kinds of things enter my mind. Really starting to think it's maybe a bearing in transfer case??? Wonder if changing transfer case lube to something thicker might help? What's involved with changing the bearing?

 

[laserjock]

That seems pretty warm on the diff for 40 miles unless it was really heavy? Is the pinion tight? Did you do a crush sleeve eliminator on it? Which style yoke is on the pinion? Straps or u bolts? Original to the truck I assume?

 

[catbird7]

I wasn't hauling anything, empty truck. It has (to my knowledge) the original sterling rearend that came with the extended cab truck (4.10). It has u-bolts on universal. Only thing I did was clean up exterior, stainless brake lines, alum diff cover and re-filled with royal purple gear lube.

 

[laserjock]

How's your fluid level? If she was dry to the hubs it may be low. I hope not. If it's vibrating could have toasted a bearing.

 

[catbird7]

Checked all fluid levels first and they're fine. Been doing more reading thanks to Oil Burner's historical collection of previously discussed problems and my money is now on loose pinion nut! Can't check till tomorrow (truck is getting dropped off on trip home from work to get state inspection) so tomorrow night should answer the question??? Sounds like this might require nothing more than simply tightening the nut? Noticed many warnings not to use impact gun. I have a 3/4 drive socket set with long breaker bar, should do the trick! Should I replace the yoke? Buy a new seal? Any advice is welcome...... Thanks!

 

[catbird7]

The "BLACK HOLE" that's what I'm going to start calling this truck! Picked up truck from state inspection (after hours, they were closed) and when trying to start, there was no "pause" waiting for the glow plugs to heat up. It went straight to blinking like the plugs were already hot (which they were not). Obviously this made it hard to start, cranked and cranked finally starting with huge smoke cloud. Not sure what's up with that, one problem at a time please........ Regarding the vibration, I did the "old school mechanic" test and it revealed a very loose pinion yoke and damaged U-joint. Ordered new yoke kit which includes yoke, nut, and two u-bolts. Also purchased two new MOOG u-joints for rear shaft. Yoke kit should be here today, I'll install tonight & report results.

 

[laserjock]

Are the splines okay on the pinion?

 

[catbird7]

Good & bad news,,,,,,,, pinion yoke kit arrived however it's incorrect. Appears to be designed for a larger U-joint (approx 4"). My joint is 3.6" (if memory serves). Anyway it's wrong and needs to go back, however I need the truck in the next few days for hunting. I removed the drive shaft and found one of the caps was completely dry, other three had grease??? Figure that one out! Regarding the yoke, the bolt was nothing more than finger tight. Removed nut & yoke, cleaned in parts washer and re-installed with loctite on threads. Used 3/4 drive ratchet with 3' piece of pipe to tighten nut. Just as I was reaching full "bench press mode", socket slipped off the nut smashed finger between pipe (mentioned earlier) and bottom side of passenger rear leaf spring. This resulted in several "gosh darn its" and a finger nail split stem to stern and yes it's black this am. Also replaced u-joint (MOOG 434) and reassembled. Didn't drive truck last evening as I wanted the loctite to solidify however I did drive it to work this morning and that definitely solved the bad vibe issue. Fear it may be short lived fix with a likely worn yoke, therefore I'll return the incorrect yoke and replace with proper size when it arrives.