Hello All,

I just purchased a '90 F-250 4X4 supercab with the Borg-Warner 1356 T-Case and the ZF 5 sp Tranny. The truck has 168,000 miles. Here's the problem:

When I drive in 2wd with the hubs locked, there is a loud metallic, bearings are shot, type of noise at any speeds higher than 35 MPH. The noise is so loud at 55 MPH that you cannot talk to your neighbor. If I shift into 4wd at high speed, the noise continues for about 5 seconds, then goes away. There is no noise without the hubs locked. I replaced both U-Joints in the front driveshaft, and still have the same problem. With the front driveshaft off, I spun the front output shaft of the T-case by hand, and it was noisy. I replaced the fluid in the transfer case, and added some prolong - still makes noise. I'm new to the aluminum - chain driven T-Cases as my previous trucks had the NP 435 4sp with NP 205 cast iron (bulletproof) cases.

Do you guys know what could be the problem? Do I need a new chain (chain stretched). Do I have a good chance fixing the prob with a rebuild kit (including the bearings).

Sorry about the long winded question. Thanks for the help!!

Jeff

 

I would guess axle shaft u-joints, not transfer case issues. It wouldn't hurt to replace them, as they are cheaper than any transfer case parts would be.

 

If you turned the T/C output shaft by hand and it sounded bad then I think you need new bearings for the T/C.

 

i agree you need some new bearings & possibly bushings. this is a fairly easy case to work on you should be able to fix it without removing the whole case. just split it apart and remove the rear shift fork by taking out the spring repainers and the chain should pull right off. and you'll be able to get at the bearing. one problem with these cases is the oil pump retainer clip breaks and the pump body spins with the shaft. if that happened to you you'll need to remove the planetary reduction because there will be a worn out bushing and possible more bad bearings. use anerobic sealer to put her back together but don't use too much any extra silicone can plug the pickup screen for the pump. have fun with this project

 

With that many miles on a 1356, I think the oil pump arm has probably worn through the case and spun around and broke, And that means a new oil pump and bearings at a minimum. Along with welding something on the oil pump arm, so it don't go through the same hole and do it again.

 

Thanks everyone for the advice on the T-Case. I might have been jumping the gun a little bit. Today, I took off the front shaft and drove in 2wd with the hubs locked. No noise. I then drove in 4wd - No front driveshaft - hubs unlocked. No noise. I then shifted in 4wd - hubs locked - no front driveshaft - no noise. I then put the driveshaft back on rotated 180 degrees. Same noise. Here is what the noise is:

It sounds and feels like a vibration. I can feel it when my feet are resting on the floorboards, and I can feel it in the transfer case shift lever. It starts at about 40 MPH, and is really bad by 55 mph. I can get it to become less pronounced if I put it in 4wd while driving and load up the front end. Once I coast, the noise is back and remains. The kid that I bought it from said that it started doing this right after he put on the 4" lift. I also have 35 inch tires. I looked at the driveshaft, and there is a pretty severe angle where it connects to the T-Case. The connection is a single U-Joint - Not double cardan U-Joint like my early Bronco, or 78 F-250. Also, I can wiggle the shaft at the slip spline about 1/8 of an inch or so.

Is the driveshaft too steep of an angle with the 4" lift? The driveshaft is 36 inches long.

Is the driveshaft shot?

If I rebuild it, should I put in a double cardan U-Joint connection?

All of the U-Joints in the front axle are solid.

Thanks again!
Jeff

 

the slip spline is supposed to be tight but none of them ever are just make sure it's greased. i know the bulk of your problems are in the t-case if i were you i'd try to get an upgrade kit for the case or get a stronger case NP there isn't a whole lot available for the borg warners and they're not very tough.

 

Spoke with the P.O. tonight. He said that the front driveshaft is contacting the crossmember during this operation, causing the vibration. I looked at the suspect area, and there is about 1/2" clearance is all. The crossmember does have marks in the area like it has been contacted by the driveshaft. The driveshaft does not have any marks on it. The contact mark (groove) on the crossmember has some surface rust (I would think this would have rubbed off during my test drive).

Do you guys think that the dynamic operation of the front end, while the driveshaft is spinning, can cause it to hit the crossmember?

This could help explain why I can get it to stop when I shift into 4wd and place a load on the shaft (less wobble and less contact).

I will grind down the contact point on the crossmember and report back. Maybe others are having, or had the same problem. Seems like this guy's friend had the same problem and fixed it the same way.......

Probably won't grind 'till Wed night, or next weekend

Jeff

 

that would do it. if you look at it from an engineering point of view when 4x4 is engaged the torque from turning the front driveshaft combined with the rear shaft torque tries to rotate the t-case up towards the floor so it won't hit unless you hammer it in reverse. in 2hi there is no torque on the front shaft so it's pushed into the crossmember the reason it doesn't make noise with the hubs unlocked is because the shaft isn't spinning but i bet it clunks into the cross member under acceleration. i glad you didn't rip the case apart like i suggested.

 

Red,

Thanks for the input, though. I originally thought it was the T-case, and my original thread made it sound that way. I guess, I'm not used to hearing the chain noise when spinning the front output yoke on the T-Case. I guess, that's a normal sound.

I have piggybacked another thread in a different forum, and another guy had the same problem with his '95 F-250, and the cause was too severe of an angle with the single U-Joint on the transfer case side of the front driveshaft. He installed a CV Joint and that fixed the problem. I would think that loading up the front end might make the vibration less in that case as well as you are transferring torque through the U-Joint and it would have less of a tandancy to vibrate.

ANyway, I will try the grinding first, and then proceed to go to the driveshaft shop. At any rate, hopefully the fix will be quicker and cheaper than opening up the T-Case. I was pretty lose to doing that yesterday (President's day) morning. It is good to network with you guys so that w can pinpoint problems with these old Fords......

My '78, although rusty, is looking more like a gem after finding these problems with the '90. I'm sure I'll be happier once all the bugs are worked out.

Jeff