'96 F-250... Decel growl in 4wd

[NotMatt]

Here's the specs:
'96 F-250 7.3, 5-speed, has a SRW 60 swapped in, unsure of what year F-350 it's from, but it's ball joint with the later style lockouts, so it's obviously later 90's.

The problem: when in 4x4, after I've run it a little and everything has had a chance to warm up and get loose, it growls briefly after I let off the gas while in 4wd... Once the slack is taken up by the engine braking in gear, the growl goes away. When accelerating there is no noise. I can accelerate up to speed, let off the throttle and it will growl for a split second until all the slack is taken up in the drivetrain, then the noise goes away. If I drive around with the hubs locked in and the t-case out of 4wd, it growls all the time once things are warmed up and loose.

I've replaced both u-joints in the front DL and that's about it. It's too cold to fart around with right now, but I need to get it fixed to be sure I have reliable 4wd this winter. The backlash feels fine on the 60, the shaft joints are in good shape, the gear oil is fresh and the level is good.

Bad output bearing in the t-case maybe? Bad pinion bearing in the 60? Suggestions or thoughts, or maybe you've had it happen before and know exactly what it is, that would be sweet! :redneck:

PS, what transfer case do I have? I don't want to go lay in the snow and try to find a tag...

 

[Not Jobless]

Pull the front diff cover off and take a look at the Ring gear.

 

[NotMatt]

Pull the front diff cover off and take a look at the Ring gear.

Yeah, that was next on my list... maybe if I cross my fingers and wish really hard it will get above freezing here soon so I can stand to work on it for more than a few minutes at a time. Or maybe I'll just man up and take the canopy off so I can fit it in the garage. :redneck:

 

[ToyZuki]

I know a guy with a huge shop not to far from your house. Wood burning stove too.

 

[CHOP SHOP]

sounds like a front output bearing or an over extended/worn slip yoke.

put it in 2x and check for play in the front pinion and tcase output.

My truck has been doing the same thing all week in I am over 35-40mph. I am going to throw that half away as soon as I can = duals:cheer:

 

[zukkev]

Hey Matt, those ZF 5-speeds are known for gear chatter when in a no/light load at lower RPMs ---I agree that you should check everything else mentioned, but if no play or damaged parts are found, try running a synthetic oil in the trans; this helped my old service manager's F250 noises---drove it that way for years before he sold it, and it's still runnin around!!!Just my .02....

 

[Dusten]

i agree with kev, the ZF-5 is known for what was always called "gear roll over" on the diesel boards. FWIW the t-case is a BW1356

 

[NotMatt]

If it was the transmission, wouldn't it do this all the time, even in 2wd? This noise I'm hearing has to be in the front drivetrain or the t-case, because it only happens when the hubs are locked in. The t-case in 2wd makes it happen ALL the time, if it's in 4x4, it only happens during the slack period between acceleration and engine braking.

[EDIT]: changed "neutral" to 2wd, mistyped.

 

[zukkev]

If it was the transmission, wouldn't it do this all the time, even in 2wd? This noise I'm hearing has to be in the front drivetrain or the t-case, because it only happens when the hubs are locked in. The t-case in neutral makes it happen ALL the time, if it's in 4x4, it only happens during the slack period between acceleration and engine braking.

When you say 'T-case in neutral', is that when standing still, or do you kick it into neutral while driving to see of something changes...???

 

[NotMatt]

When you say 'T-case in neutral', is that when standing still, or do you kick it into neutral while driving to see of something changes...???

That's while driving around, and to clarify, I meant 2wd, not neutral, sorry. It's mainly at higher speeds that it does this, 25mph and above probably. Basically the 4wd works fine and shifts in and out no problem, but when there's no load one way or the other on the front drivetrain (accel or engine braking), it will make the noise. If the hubs are locked and the t-case is in 2wd, driving around it will make the noise constantly.

 

[zukkev]

Does this noise, when in 2wd/hubs locked, sound like tire rotational speed kinda noise, or much faster as you speed up...If it sounded more wheel speed related-I'd go after something in the front axle; Otherwise, you may be looking a future Tcase issue.

 

[Dusten]

when my brother drove for like 60 miles at freeway speeds on dry pavement in 4wd, with 35's his truck was making a similar noise. we replaced his t-case, noise was gone

 

[DEANS4.3TOYO]

its a 1356 t-case and the pump inside wor out the front case and it broke threw and it pulled the tube off the pump and its not getting lube to the gear train you need to stop driving it and pull the t-case out and apart and you will need a pump once you get in there you will see the front case is warn out. when you get your new pump there is a braket that bolts to it and you will have to weld a little pease of metal to it and make it slide down in the case and be supported in a larger spot and wile you are in there check the range fork that is the fork that goes on the little gear that goes in the planet they have a tendensey to where out. good luck.:corn:

 

[NotMatt]

its a 1356 t-case and the pump inside wor out the front case and it broke threw and it pulled the tube off the pump and its not getting lube to the gear train you need to stop driving it and pull the t-case out and apart and you will need a pump once you get in there you will see the front case is warn out. when you get your new pump there is a braket that bolts to it and you will have to weld a little pease of metal to it and make it slide down in the case and be supported in a larger spot and wile you are in there check the range fork that is the fork that goes on the little gear that goes in the planet they have a tendensey to where out. good luck.:corn:

Merry Christmas to me! uke:

Do you have any links to more information on this? Should I quit driving the truck completely or just not in 4wd? It sounds like you're saying the pump is not lubing the t-case, but for reference, i do NOT hear this noise at all in 2wd with the hubs unlocked, the truck drives and sounds normal then.

Guess it's good I've got my beater 4runner to drive around in the snow.

 

[xraidedj]

I just wanted to drop by matt and say MERRY christmaz! Doesn't look like we will be towing up to tonaskit in your ride...

 

[NotMatt]

What the hell...

I yarded out the front driveline today up at my parents' place, and drove the thing with the hubs locked in and the t-case in 4wd all the way back to Wenatchee at 60mph.... no noise!

I can wiggle the slip on the driveline side to side a little with my hands, but it doesn't feel worn at all. Tomorrow I guess I'll take the bands off the boot and pull it apart and see if it has any wierd wear on it. Doesn't feel like it, but it's probably packed with grease.

I guess I'll probably still end up pulling the t-case though... seriously **** this damn truck, I should have bought a 12 valve Dodge.

 

[Turtle Bite]

What the hell...

I yarded out the front driveline today up at my parents' place, and drove the thing with the hubs locked in and the t-case in 4wd all the way back to Wenatchee at 60mph.... no noise!

I can wiggle the slip on the driveline side to side a little with my hands, but it doesn't feel worn at all. Tomorrow I guess I'll take the bands off the boot and pull it apart and see if it has any wierd wear on it. Doesn't feel like it, but it's probably packed with grease.

I guess I'll probably still end up pulling the t-case though... seriously **** this damn truck, I should have bought a 12 valve Dodge.

I know how you feel, my rear driveline slip is worn out and vibrates, I need three front axle u joints, one of my rear springs just fanned out, and on and on. I suggest you give up before 227K, its not worth it to keep going:flipoff:

 

[nevada]

What the hell...

I yarded out the front driveline today up at my parents' place, and drove the thing with the hubs locked in and the t-case in 4wd all the way back to Wenatchee at 60mph.... no noise!

I can wiggle the slip on the driveline side to side a little with my hands, but it doesn't feel worn at all. Tomorrow I guess I'll take the bands off the boot and pull it apart and see if it has any wierd wear on it. Doesn't feel like it, but it's probably packed with grease.

I guess I'll probably still end up pulling the t-case though... seriously **** this damn truck, I should have bought a 12 valve Dodge.

what about the front output? any play there?
could it be the nut backed off a bit? or the bearing is bad/loose?

 

[NotMatt]

what about the front output? any play there?
could it be the nut backed off a bit? or the bearing is bad/loose?

No play in the front output, spins freely and does not feel sloppy or rough at all.

 

[NotMatt]

Here's a wild thought that just dawned on me. F-350's of this year have a double cardan CV on the front driveline at the t-case.... correct?

Mine doesn't.... they used the F-250 standard u-joint driveline, and upon closer inspection, the angle looks mighty steep. I think this truck is also lifted a slight bit over even the height of an F-350 of this year.

I have a friend who is going to let me look at his F-350 tomorrow and swap drivelines if it's a CV style on his, and we'll test my theory out.

Hopefully it's that simple... I can take the DL down to the local place and have him put a 1330 CV on the end and call it good. I believe I will also have to swap the yoke out on the t-case. Hopefully the driveline guy has it or can order it.