Shudder I can't find after adding 4" lift

[colorado_tahoe]

Shudder I can\'t find after adding 4\" lift

I've been trying to locate some bad shudders between 25 & 35 after putting a 4" suspension lift on the truck. No lift blocks, and did not turn the axle to compensate for the angle. Anybody have any suggestions or ideas what it may be??

Colorado_Tahoe

Ugly Truck, Pretty Wife

 

[BLzr4x4ngkid]

Re: Shudder I can\'t find after adding 4\" lift

DRIVE SHAFT!! Might be the drive shaft. Mine did the same without a lift. My U-joints were screwed and it shudder BAD!! Check that and see. I could grab my drive shaft and shake it. HMMMMMMM don't think it's supposed to do that. HAHA Check it out. I'm sure you will get some more ideas from the other great guys. Good luck brutha

"Crutch"

"What me get stuck? NEVER!!"(Famous last words)

 

[BlueKnight]

Re: Shudder I can\'t find after adding 4\" lift

check your U joints.... they are now working at a new angle they may be almost worn to. Check the mounting of them also

 

[OneInTheSun]

Re: Shudder I can\'t find after adding 4\" lift

Same thing with mine after a 4" Superlift (all new springs). Like the others said - check the simple stuff first - make sure the balance weight is still on the driveshaft and check the u-joints for wear. If it's not that, the u-joint angles are probably off - the angles have to be pretty close to one another to cancel out each other's natural vibration/motion (or something like that). To remedy my situation, I lowered the transfer case a bit, but the u-joint angles are still about 3 degrees apart, so I'm going to replace the shims that came with the springs with larger ones.

<font color=blue>Rob
85 K5</font color=blue>

24 beers in a case, 24 hours in a day - Coincidence?

 

[Corey-88K5]

Re: Shudder I can\'t find after adding 4\" lift

Your transfer case output shaft & the pinion yoke should be the same angle. If they aren't, this could cause your vibration. If you need to change your pinion angle, talk to your local 4x4 shop OR a local axle shop. They should have axle shims. Just get the correct one to fix it. If you need to drop you case (which I would NEVER do...) you can support the t-case with a floor jack, take the spacers out from under the crossmember for the t-case and put them between the chassis and crossmember. Another thing you could do it go to the local steel mill and puchase the steel and make a "drop kit". Just keep in mind, if you have a full time case (203) doing this will increase your front shaft angle, and just cause the same if not worse problem on the front shaft.

Corey
88K5

<font color=red>Girls Like Guys In Bow Ties
http://www.geocities.com/corey_perez

 

[Steve88]

Re: Shudder I can\'t find after adding 4\" lift

I still don't get that t-case drop thing. I get the steps but I don't get the concept. I'm looking at it and doesn't it drop the tranny and engine? If so doesn't that put stress on the engine mounts? Someone said if you do it without a body lift you can come pretty close to the firewall with the distributer?

<font color=red>Steve88</font color=red>

88K5 Silverado
[email protected]

 

[Corey-88K5]

Re: Shudder I can\'t find after adding 4\" lift

The drop kit for the T-case will tilt the motor, trans & t-case on the motor mounts. The motor mounts pivot and allow the t-case to drop lower. The main problem is the front shaft will be put a larger angle. This is usually a larger problem with 203's. And yes, it will place the dist. closer to the fire wall. You could replace the dist. with a C.F.I. (Crank Fired Ignition) But that would be expensive. Another option would be to move the motor further forward, and either remove the mechi. fan from the water pump and replace it with a electric fan.

The main purpose of doing a t-case drop is you can tilt your pinion up on the rearend and it allows the driveshaft to run at a (total of) less angle.

Best of luck, and if you need any other options, lemme know.

Corey
88K5

<font color=red>Girls Like Guys In Bow Ties
http://www.geocities.com/corey_perez

 

[bigjbear]

Re: Shudder I can\'t find after adding 4\" lift

If your driveshaft and u-joints check out ok and you have a part time case, drop the case about 1". All this is, is a set of spacers that go between the frame and crossmember. I have had no problem with the distributor cap hitting the firewall and I have an HEI ignition and that is about the biggest cap I know of. After I dropped my case all my driveline vibes cleared up. I have an NP205 case and a double u-joint on my front shaft, so a slight increase on the front output is not that big of a deal. If you need more info write back. Jim

BigJBear '80 GMC

 

[_DeeVee8_]

Re: Shudder I can\'t find after adding 4\" lift

Definetley check the drive shaft for movement(side to side)

and look at the u-joiints-- they are almost always the culprits..


4" lifts aren't that extensive to warrent adjusting angles of T-cases and engine to t-case angles.(unless otherwise noted)

I ended up rebuilding all my u-joints to cure the chatters i had too.
Rancho 4" lift
-Dv8

The only gun control this country needs is a steady hand.-- bumper stcker i saw once

 

[Steve88]

Re: Shudder I can\'t find after adding 4\" lift

Corey, excellent description. That definately clears it up for me. Had no idea you could pivot a motor on it's mounts. I guess I should take a closer look under the hood.

When I do my lift then I'm going to not plan on dropping the t-case (208) but know it's an option. I'd rather see how it goes and not do the drop unless absolutely unavoidable and as a low cost option to other, and probably better, choices.



<font color=red>Steve88</font color=red>

88K5 Silverado
[email protected]