Hi all
Two of my friends and I own 1997 f350's with 460ci engines. We have all lifted them, one is lifted 8 inches and the other two are lifted 6 inches. All of our trucks transfer cases have a growling sound only when decelerating in four wheel drive. When were accelerating the noise goes away. These trucks ran perfectly quiet when in four wheel drive before the lift. Is this a common problem when lifting these trucks? (all u-joints are good) I am hoping someone here can shed some light on this problem we're having. I have used the search function for the site but couldn't seem to find anything.

 

DId you lengthen the drive shafts? If not, you need to, they are ready to pull apart

 

The one with 8 inch lift has had a new shaft made. I also had a 96 f250 I had a couple of years ago I did a straight axle swap with no lift, I just put f350 stock front springs and axle under it and it did the exact same thing as the trucks we lifted.

 

The 6" lifted trucks need them too. You are lucky to have 1" if splines engaged on the front shaft

Did you get the right shaft for the F250/d60 swap? What trans was in the truck and what trans was the donor truck?

 

Have you personaly had this problem, and was that the fix? I belive we have quite a bit more than 1" of spline engaged in the shaft on the 6" lifts. These lifts were done a couple of years ago and I don't quite remember how much exactly...I'll check later. As far as the f250/350 swap goes I don't know what trans the donor truck was and I used the shaft (with the appropriate joints to make it work) that was original to the f250. There is a very minimal distance the height of the pinion position from a stock f250 to f350...the drive shaft angle doesn't change much.

 

Yes. I have had personal experience on about 15 of these lifted f350s.

As for the f250/dana 60 swap…. The length and the angle does change, hence the different drive shaft from a F250 and F350.
I will assume you also got the front yoke from the donor truck when you put in the F350 drive shaft?

 

1) On my friends lifted 1996 f250 (with independent) 6" lift he checked and has just over 2" of spline engaged on his stock shaft. Are you saying this is causing the growling transfer case noise? If so, why? I believe his front shaft has just 1 u-joint at each end where as the f350 has 2 joints at the transfer case. When lifting these fords what shaft do we need?

2) Have you had this same noise and fixed it just by lengthening the shaft?

3) Do we need to have f350 shafts?

4) What shaft do we need and how much spline should be engaged?

 

The 1997 f350 with 8" of lift has had a shaft lengthen and has between 3.5"-4" of spline engaged. It has 2 joints a the t-case and one at the pinion. It growls just like the others....only when you let off the accelerator.

 

In your 1st post you had (3) f350s and now you are talking F250s. Which is it?

2" is about optimal engagement(that is stock) so I don't see how a truck lifted 6" still has the stock amount

For the F350 with 8" of lift, did he clock the T-case to correct driveshaft angles?

 

1) Yes...my friends and I all have a f350 lifted 2-6" and 1-8". The 6" trucks have the stock shaft and the 8" has one that has been lengthen. I also have a 96 f250 and did the axle swap and my friend also has a 96 f250 with a 6" lift. They ALL growl only when you let off the gas. I was just looking for someone to tell me......(when you lift a 97 f350 6" you need to do this) so they don't growl, and for 8" lift (you need to do this) so it dosent growl. Finally when you do a 250/350 swap (you need to do this) so it dosent growl.

2) The t-case is not clocked. How much does it have to be clocked? If you clock the t-case we would then have to modify the cross member...correct?

 

there is no set standard, just guidelines.

I have never had an OBS over 8" so I can't say from personal experience on that. but my 96 when I had it at 8" of lift, I could NOT use 4wd because I would rip the front shaft right out of it(it was just there for show)

All my other trucks were ok with 4" of lift

Other peoples trucks I have lifted, some need driveshafts at 6" of lift, some were "ok"

As for f250s getting D60s, EVERYONE needed the f350 yoke and drive shaft so they did not vibrate over 40mph

 

All of these trucks Im describing have zero vibration...they feel perfectly smooth. The trucks you lifted 6" did the t-case growl when letting off the gas? Just lengthening the shaft for more spline engagement was the fix??

I am looking at buying a 97 f350 crew long box but I would want to put a 6" lift on it. I am hesitant to buy another one of these trucks if I cant eliminate this problem because I wont leave it stock. I like them lifted. I plan on taking trips with this new truck I might purchase and I want it to be in proper working condition.

 

When accelerating there is no noise...only when letting off the gas. It kinda sounds a bearing scored up when decelerating. What is happening in the t-case that is actually causing that noise.

 

Are all these trucks autos? If manuals it could be gear rollover noise.

I would add the double (double cardon?) joint at the t case like the 350 has stock, the sharper angle could cause a noise from the regular ujoint on decel. Think about how wonky your front wheels feel when you turn sharp in 4WD, same principal.

Decelerating would be putting opposite forces through the big chain in the t case, that means the opposite side of the chain is going to be slack, maybe its hitting another part or the outer case on decel? What are you using for tcase fluid?