Truck help

Discussion in 'General Discussion' started by kckndrgn, Sep 11, 2009.

  1. kckndrgn

    kckndrgn Monkey+++ Moderator Emeritus Founding Member

    Call all gear heads!!!

    I've got a problem with my "new" old truck. The truck is an '87 F150 with 89,000 miles on it. When i put the truck in gear (automatic :( ), I hear a "clank".

    At first I was told that it was prolly the U-joints. I checked them, no movement what so ever. I got back under the truck just now and I was able to twist the drive shaft and 1" or so in both directions and I was able to make the "clank" sound. It was coming from the differential.

    My FIL said, it may be cheaper to by a salvaged complete rear axle.

    I'm not sure my skills are up to the task of disassembling the differential and fixing it, I know there are many moving parts in there but is it that difficult?

    Thanks in advance!!
  2. ghrit

    ghrit Bad company Administrator Founding Member

    I'm guessing you have too much end play on the pinion. I'm guessing it is well worn, quite possibly due to inadequate lube. It can be adjusted, but you gotta look at it and will need a dial indicator (and shims) to do it right. The skill required is limited and the parts are not expensive, usually. And the chances are pretty good there is less to break if you take off the rear cover plate for a look rather than messing with a complete axle change, so I'd start with that. If repairable, go for it. Otherwise, your FIL is right, and be prepared to deal with rebuilding the brakes when you change the axle.
  3. SLugomist

    SLugomist Monkey++

    Have you changed the ATF, and filter?
  4. WestPointMAG

    WestPointMAG Monkey++

    Fords have a removable PIG, the PIG is the carrier for the gears. All you have to do is slide out your axles unbolt the center PIG, remove it, reinstall the new/used one then put your axles back in. You do not need a pig from a truck, some car ones will fit, but if the ring gear is bigger you will may have to do a little grinding to get it in the hole. If you decide to change the pig this would be a good time to see if your gears match you driving. If you live on the flats like I do then high gears will work better if you live in the hills low gears will be better. My 77 Chevy ½ ton has 2.78:1 gears in it and on the flats will run 110+ but it will not climb a hill for nothing so if I lived where there were hills I would rather have 3.73:1 and in the mountains 4.11:1 would do a good job.
  5. kckndrgn

    kckndrgn Monkey+++ Moderator Emeritus Founding Member

    have not yet changed ATF, I was planning on doing that. May do that along with the rear end work.

    WPM, PIG? Pinion Gear? My current differential is a 3.55.

    ya know, free trucks are expensive!!!
  6. WestPointMAG

    WestPointMAG Monkey++

    they can but not like $20,000 fir a new one.
  7. kckndrgn

    kckndrgn Monkey+++ Moderator Emeritus Founding Member

    My FIL said he can help me rebuild my diff. I'm just not sure, 100% if that is what I want to do. I can get an entire rear axle assembly from for 600.00 shipped w/ 3 yr warranty.

    Or, I can get a kit that has all the bearings and gears in it. The price for the kit varies and I'm still trying to figure out which one I would need. I know, currently my diff is an 8.8, with 3.55 gearing. I would like to keep it at the same gearing. Looking here , there are a number of different kits available. I'm thinking p/n 32380 or 32380E would be what I need.

    WPM, do you know if there are any special tools needed to doing a rebuild? I've read that I need a torque wrench to set the pre-load.

    I guess I could just get the new axle, then sell the old one as is, I'm sure there is someone out there that could use parts off of it.

  8. Quigley_Sharps

    Quigley_Sharps The Badministrator Administrator Founding Member

    let a shop set up the gear lash on the third member and then install it.
    don't get the lash right and guess what you will be back to where you are now, as ghirt said low lube or the lash was preloaded wrong.
    I have rebuilt many of the 9" third members in my broncos over the years, it can be done, but I ruined 2 before i finally started getting it right.
    your mileage may vary.....
  9. ColtCarbine

    ColtCarbine Monkey+++ Founding Member

    Popcorn, get your popcorn.

    I'll come back to this tomorrow evening when I'm a little more coherent.

    Properly setting up a rear differential that is going to last takes time, patience, a lot of trial and error, a good assortment of shims and a few tools that aren't in the average Joe's tool box.

    Many of folks have done this repair, as it's not hard to swap out the parts but............

    If the vehicle is making a clank sound when engaging in gear, usually it's worn out u-joints or a rear differential that's going to grenade on you down the road.

    Generally speaking if an automatic transmission is is need of a fluid and filter change it will slip. Best way to describe it is, if you have ever had a manual transmission that is in need of a clutch a slipping auto transmission does about the same thing. Lots of RPM's with NO-GO done the road.

    If I had the time I'd post up what is involved in properly setting up a differential, it is not for the faint of heart or anybody that hasn't done much wrenching.

    $600 for a rebuilt differential is a smoking deal if it's from a reputable repair shop that stands behind it's warranty.
  10. kckndrgn

    kckndrgn Monkey+++ Moderator Emeritus Founding Member

    The U-joints have been checked by 3 different people, we have all concluded that they are good, zero movement with them.

    I can literally turn the drive shaft about an inch and reproduce the "clank" sound, coming from diff.

    I've ordered the complete axle, no need to waste my time right now trying to rebuild it on my own.

    There is no slipping that i can tell with the transmission. And yeah, I've had a manual transmission where the clutch went out.

    Thanks all, going to go start soaking all the bolts in penetrating oil, try to make it a little easier to get those buggers loose from all the rust on them.
  11. WestPointMAG

    WestPointMAG Monkey++

    Candle wax works better you only need enough heat to get the wax to wick along the threads. The wax will go where no oil can. We use it in the shop a lot to get stuff to where we can move it, if you can get it to move it will come off.
  12. kckndrgn

    kckndrgn Monkey+++ Moderator Emeritus Founding Member

    WOW, it's amazing what you learn here. I have never heard of using candle wax, but I'm going to give it a try.

  13. Tango3

    Tango3 Aimless wanderer

    Pop the cover look for a broken pinion gear perhaps the bolts(
    (all ) are sheared on the pinion?( er..'scuse me " ring gear")
    ( unlikely), I've never set one up but understand the lash and engagement takes a trained eye,shims, dial indicators the correct "crush" on the pinion washer and understanding what "correct" looks like: I bent over $1200worth for a ford dealer to rebuild mine...I'd personally go for the $600 complete one, just sayin..:oops:"it aint a job for the clymers set."
  14. kckndrgn

    kckndrgn Monkey+++ Moderator Emeritus Founding Member

    yup, got a new/used (with warranty) axle coming in. Since I'm swapin' the axle out, I'm going to put in new shocks, new brakes (if needed), and on the front end I'm going to replace the fuel pump. I'm hoping that is the reason for a rough idle that I have. It's a mechanical pump, so with the truck sittin' for 2 years with no significant run time, it may just need replacin', and it's cheap.

    I've also found a new electronic ignition module. I'm not going to swap it out, just going to seal it in an ammo can, you know, just incase ;)

    Thanks all. I will update ya when the axle comes in and I get it replaced!
  15. Tango3

    Tango3 Aimless wanderer

    Usually a bad mechanical fuel pump presents as a gasoline leak dribbling out the tiny vent hole ( means the diaphram is bad.)but goodluck wid da beast!
  16. WestPointMAG

    WestPointMAG Monkey++

    Don’t confuse the poor man it is a Ford.
  17. Tango3

    Tango3 Aimless wanderer

    Sorry, I have first hand knowledge of the kind of carnage a busted off pinion tooth can cause. nasty...
    yeah it was a ford s'wut :)
  18. kckndrgn

    kckndrgn Monkey+++ Moderator Emeritus Founding Member

    OK, got the "new" axle in today. This is a used axle with a 3-year warranty. First thing I did was move the part where the drive shaft connects to the differential. I was able to move it about the same amount as what is currently on the truck, but no sound (clank).

    Should there be any movement in this part? The axle is still mounted to the shipping pallet, I haven't done anything with it yet. hopefully this weekend I can get the axle swapped out, if it's good.

    Thanks all
  19. Tango3

    Tango3 Aimless wanderer

    Perhaps the graphics in this primer will give you an idea of what is happening inside the diff as your turn various parts , it's (the differential is) pretty ingenious...
    your problem could be broken spiders, the ring gear or a pinion or bad axle splines gotta inspect know, pull thecover ( overa drain pan!lookfor metal fragments or busted gear teeth in the lube) twist the pinion ( input) and see what is moving or not inside to find where the slop(noise) is coming from. :)
  20. kckndrgn

    kckndrgn Monkey+++ Moderator Emeritus Founding Member

    false alarm. i thought that both wheels were "locked down" on the pallet but they weren't so, I was actually turning the wheels.

    After holding down the wheels I found there was no play at all in the differential.

    Now the fun begins!
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