Eagle drop box input cover loose

Kitt · November 04, 2014, 12:46:18 PM

Hi everyone.

Today I noticed that my drop box was dripping oil after driving it and found that all of the bolts holding the input shaft cover and shims was loose. No bueno! The drop box is tight to the differential and no issue there.

What's a good way to take care of this? Can I just tighten up (re-torque) the bolts again and be done with it? If I did that, should I remove the cover and shims and clean all of the surfaces up? I had read that a bad bearing can make the bolts loosen - should I be pulling out the input shaft/gear/bearings and having someone inspect the bearings? Is it difficult to get the shaft/gear/bearings out?

If the latter, and I end up getting new bearings, is there anything else I would need? Is it difficult to get the shims just right (never done that before, so I'm asking). Should I dump and refill the drop box and differential oil just in case?

Thanks. Any words of wisdom and recommendations are welcome. We're hoping to get back on the road next week...

chessie4905 · November 04, 2014, 04:58:03 PM

Check closely for worn or bad u-joints- vibrations

luvrbus · November 04, 2014, 06:23:56 PM

Kitt,you need to pull the drop box and replace all 4 bearings Jefferson has the new shim packs and gaskets the bearing need to pre loaded and the end play on the input shaft needs to be .001 to .005 they are close some time the inner bearing race need to be shimmed out to achieve it

Not a hard job to rebuild the drop box on a Eagle but they need to be right or they will come back to haunt

Kitt · December 05, 2014, 06:31:47 PM

I ended up taking the bus to a shop and bought all of the parts (bearings, shims, gaskets) from Jefferson and got them over there. I went over there today to see it and they showed me the input shaft (#13 in the parts book, Rockwell 3280-S-4622) and a bunch of the threads in the middle of the threaded area are loose - meaning that the threads are there and contiguous but at a certain point they're no longer part of the shaft, if that makes sense - probably near where the bolt was that held the end yoke on. My best guess is that the shop that put the HT740 on for the previous owner, along with the new driveshaft, didn't do something right. No issues were found with the drive shaft. The good news is, at least, is that the old bearings seemed good and there was no metal in the oil.

The shop is trying to find a new input shaft (from Jefferson and other sources), but I figured I would ask here if anyone has one they'd part with... Also, if anyone has a sketch or write-up on how their drop box was set up with the new yoke end and drive shaft for a 740 that may be helpful if we/they need to redo what was done before.

luvrbus · December 05, 2014, 06:52:59 PM

Sad they left the thrust washer out behind the yoke I'll check my stash I may have one but these MCI guys have been killing me on drop box parts

I know Gary at B&B in Vegas will have a used one he has drop boxes scattered all over the place give him a call first, the price of the shaft and washer at Jefferson will give you the big one lol the washer cost 55 bucks

Kitt · December 05, 2014, 07:49:05 PM

Thanks, Clifford. I think there may have been a thrust washer in there (that must have been the other part they showed me that I don't see in the parts book) but it was pretty scratched up, so that'll need to be replaced for sure. I'll check with Gary.

Kitt · January 12, 2015, 10:34:54 AM

The shop used 70w90 synthetic in the drop box and rear differential but there is some seeping from where the metal shins are. The shims were new and everything was cleaned and torqued correctly. What are some of the common issues and what's the best way to fix the seeping? Should they be using a straight 90w oil instead?

chessie4905 · January 12, 2015, 11:12:41 AM

Clifford, I better check the drop box on my GMC for looseness. Oh wait, I don't have one.

luvrbus · January 12, 2015, 11:20:47 AM

The drop box and differential are supposed to be 85/140w the shims will seep for a while just check for tightness again,there are 2 holes in the rear of the box that require bolts if something is not attached in that spot and the drop box use flat steel washers not lock washer with lock washers they seep

chessie4905 · January 12, 2015, 11:36:53 AM

Some Loctite sealant would be good to use on those bolts.

Kitt · January 12, 2015, 11:39:51 AM

My manual said EP90w, but we will do the 85/140 - they just have to order some. Thank you!

luvrbus · January 12, 2015, 12:03:56 PM

Hum my manual says 75/90 below 10 degrees 85/140 above 10 degrees it's a model 15 manual but the drop box and differential are the same

Kitt · January 12, 2015, 01:07:45 PM

Ok, that makes sense. It's cold up here now, but I don't plan on hanging around in this cold too long or driving much when it is below 10, so we're going with the 85/140.

Kitt · June 23, 2015, 09:55:29 AM

Cliff, about 7,000 or so miles into our trip I noticed the input cover loose again. I retorqued all of the bolts to 60 ft-lbs and drove another 3,000 miles and didn't notice any issue. Any thoughts on what could have caused this a second time? Anything I should look into (hard shift? Motor mounts?)

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RJ · June 24, 2015, 06:47:50 PM

Quote from: luvrbus on December 05, 2014, 06:52:59 PM
Sad they left the thrust washer out behind the yoke. I'll check my stash I may have one, but these MCI guys have been killing me on drop box parts.

Clifford -

Is the drop box in my MC-5C the same one that Eagle used? According to my Final Vehicle Record, I've got a Rockwell R164-WX37 rear axle.

TIA,

RJ