Transfer case-cross member bolts

I've noticed that I have vibration at high speeds on the freeway, only when not on the throttle though. I happened to notice that it seems my transfer case is not bolted to the cross member and I think this may be the cause.

What size bolts do I need for this? I'd like to do this tomorrow, along with a few other pieces of maintenance.

The transfer case is not supposed to be bolted to the crossmember. It is bolted to the transmission, which is connected to a transmission mount, which is bolted to the crossmember. Do you have a lift? Worn u-joints? Done any work that you may have forgotten to tighten?

we need info 'bout your rig. good possibility bad u-joint in driveshaft. ended up being the front DS in my case

Crewdude007 said:

The transfer case is not supposed to be bolted to the crossmember. It is bolted to the transmission, which is connected to a transmission mount, which is bolted to the crossmember. Do you have a lift? Worn u-joints? Done any work that you may have forgotten to tighten?

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Oh, I see. Well good thing I didn't just bolt it down then.

4.5" Rusty's with rear leafs, I removed the bottom leaf from the pack and also took out the 1.5" spacers in front that the P.O. had put on, but the vibration had been there before that. Since I've had it actually. Lowering it a little made it better.

I replaced the rear u-joint a little while ago, and that helped with a different problem.

jbmoose said:

we need info 'bout your rig. good possibility bad u-joint in driveshaft. ended up being the front DS in my case

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Aside from the above, 90 4.0 4dr 4.5" rusty's. 187k, auto. 33" worn out AT's.

Since that doesn't seem to be my issue, let me describe the issue for you guys a little more.

The shake only happens above 60mph, and only when I'm not applying torque to the drive train. So, like going down a hill and letting off the throttle is mainly when it happens. Stepping on the throttle while going down the hill stops it (if I step on the throttle enough) but throwing it into neutral and revving the motor to any speed does nothing for the shake.
I feel nothing in the steering wheel, so I know it's not my front end.
One day when it was real rainy out I decided to drive in 4-Hi, and this actually made the shake much less..so I've been driving in 4-Hi haha.

Only recent work I've done is replace my sheared tie rod on trac bar (scary shit), remove those coil spacers, and 1 leaf from the rear...but like I said the shake has been there since I got the heep.



Oh, yeah taking a look I see what you mean how the Tcase isn't bolted to the cross member, but I remember some time ago noticing a lack of bolts in the cross member...so maybe the trans is just not bolted to it? How many bolts should there be, and where?

It really sounds like the front DS. Easy way is to take the front DS off, drive it around. It would probably take 20 minutes total. It's only 8 bolts. But if the DS is unbalanced, has a bad u-joint, or a poor angle, that vibration will go away with removal. i went through this exact same chit

jbmoose said:

It really sounds like the front DS. Easy way is to take the front DS off, drive it around. It would probably take 20 minutes total. It's only 8 bolts. But if the DS is unbalanced, has a bad u-joint, or a poor angle, that vibration will go away with removal. i went through this exact same chit

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Okay, I will try this tomorrow when I do some of the other work.

That would be a sweet fix.

this confuses me a bit, since there is absolutely no way to bolt the transfer case to anything it's not supposed to be... are you talking about the 4 nuts in the small holes at the center of the crossmember?

When you pull the front driveshaft, you're going to need a GOOD quality 5/16 ratcheting box wrench, there isn't space for a socket and ratchet in between the yoke and the transfer case. A 6 point 5/16 socket should be used on the bolts holding down the straps at the axle end.

I was able to use a little 1/4" drive ratchet and short socket (8mm I think?) with success in that spot, but it is pretty tight.

I got the shaft bolts out relatively easily...however it almost killed me. Forgot to block my tires, and the second I tapped the front shaft with my hand it popped out and the jeep started rolling back. No idea how I got out and slammed the brake, I'm thankful I am not hurt but I'm even more thankful and glad no little kids or people happened to be standing behind it when it happened. Stupid mistakes are the fastest way to learn something.



Anyways, back on topic...got the front DS removed and it got rid of the highway shake I had when not on the throttle above 55mph. However, it brought back the shake/jumping when I accelerate from a complete stop. It only happens if I come to a complete stop, and then accelerate which causes my center console to shake in 4-5 distinct "bump-bump-bump-bump-bump" where it seems to just move up and down then go away once I've gotten to 3-5mph.

I would like to fix that, as well as the issue with the front DS...which it seems I just need to replace it's U-Joints? I'm hoping that's all it needs. Is there any difference between some NAPA Joints and somewhere else such as 4WheelParts?

kastein said:

this confuses me a bit, since there is absolutely no way to bolt the transfer case to anything it's not supposed to be... are you talking about the 4 nuts in the small holes at the center of the crossmember?

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Yes, exactly what you said. I hadn't been under my Jeep in a while since I've been busy with school, so I just made a quick thread and an assumption. Haha clearly it was a wrong assumption.