1999 4x4 2 Door Tahoe

[Rob Scariano]

WOW. Nice Ride

What degree shim did you use on rear differential ? Did you go with CV shaft ?

So after several weeks of toying around with driveline issues, I found the secret sauce to eliminating 2 door driveline issues. Too bad the lift manufacturers don't offer this info up front.

So, I ended up with a CV rear driveshaft. That alone eliminated most of the driveline vibration. However, the rear ended had to be shimmed 8 degrees. After the CV shaft and shims were installed, it ran great!

 

[bunchz71]

So after several weeks of toying around with driveline issues, I found the secret sauce to eliminating 2 door driveline issues. Too bad the lift manufacturers don't offer this info up front.

So, I ended up with a CV rear driveshaft. That alone eliminated most of the driveline vibration. However, the rear ended had to be shimmed 8 degrees. After the CV shaft and shims were installed, it ran great!

WOW, 8 degrees and a CV ? Did you have a tapered block on your lift kit or just square ?

 

[Dneel81]

I had to put a CV shaft in mine too. Fortunately the shaft and pinion are within about 1.5 degrees of each other. Mine only vibrates when I really get on it in 1st or 2nd gear or really drop the clutch. The poor 10 bolt is not looking like it's going to last with the 37" MT tires however for now it'll do until I can find that elusive 14 bolt semi float rear end.

Glad you got yours figured out. I'm sure i'll have to redo mine once the new rear end goes in

 

[Rob Scariano]

The

WOW, 8 degrees and a CV ? Did you have a tapered block on your lift kit or just square ?

It's an RCX 6" kit. It was tapered. However, it's not enough for the 2 door. The 2 door has a much shorter driveshaft and Rough Country doesn't take that into consideration when they say their kit fits "all models".

The worst angle was up at the driveshaft yoke. The CV fixed that. However, when you use a CV shaft, the angle at the pinion has to be 0. As such, we had to install pinion shims. Drives great now. And I will tell all here on this forum, I feel like I gain 30HP from having a corrected driveline angle. For anyone using an extended driveshaft on a 2 door Tahoe and not a CV, spend the extra dough. It was 300 for a driveline shop to modify my driveshaft and another 150 to have the shims installed.

 

[bunchz71]

The



It's an RCX 6" kit. It was tapered. However, it's not enough for the 2 door. The 2 door has a much shorter driveshaft and Rough Country doesn't take that into consideration when they say their kit fits "all models".

The worst angle was up at the driveshaft yoke. The CV fixed that. However, when you use a CV shaft, the angle at the pinion has to be 0. As such, we had to install pinion shims. Drives great now. And I will tell all here on this forum, I feel like I gain 30HP from having a corrected driveline angle. For anyone using an extended driveshaft on a 2 door Tahoe and not a CV, spend the extra dough. It was 300 for a driveline shop to modify my driveshaft and another 150 to have the shims installed.

My kit is a 6" RCX as well. Exactly the issues I had. I ended up with a 3 degree and extending my shaft. Still has a little vibration but only noticeable when the cruise is set and going down a big hill when the engine idles down. Annoying as crap. sounds like I need the CV as well.

 

[Rob Scariano]

My kit is a 6" RCX as well. Exactly the issues I had. I ended up with a 3 degree and extending my shaft. Still has a little vibration but only noticeable when the cruise is set and going down a big hill when the engine idles down. Annoying as crap. sounds like I need the CV as well.

The CV shaft will fix it completely. In addition, the vibration is bad because it will wear out the rear transfer case seal. Long term, it can wear out the transfer case if it goes on too long. You won't regret the CV shaft. I felt like I gained HP from the new shaft and pinion shim. The shop I spoke to said that the harder angle will make the engine work harder. As such, power will increase with the correct shaft and fuel economy will improve. You won't regret it!!

 

[jerryjoe28]

works well?

SOOOO much better thank you for taking the time to send me pics of yours and recommend how to fix it!

So after several weeks of toying around with driveline issues, I found the secret sauce to eliminating 2 door driveline issues. Too bad the lift manufacturers don't offer this info up front.

So, I ended up with a CV rear driveshaft. That alone eliminated most of the driveline vibration. However, the rear ended had to be shimmed 8 degrees. After the CV shaft and shims were installed, it ran great!

x2 I didn't realize how bad mine was before I fixed it....... WOW

 

[jerryjoe28]

WOW, 8 degrees and a CV ? Did you have a tapered block on your lift kit or just square ?

im planning on dumping my blocks and going with lift springs think that will require something like a 11 degree shim. @bowtiefreak isn't that what you run?

 

[bunchz71]

Dropped mine off at the shop today to get the 4.56 gears installed. Can't wait to see the difference it makes.

 

[bunchz71]

OK, got the Tahoe back today. Runs good with power. Now that the engine basically has no load on it @ 75 MPH, it feels like with the cruise control on, it gets up to speed in OD, then the motor basically has no load on it, so it kind of feels like it coasts for a brief second and then accelerates back to 75. Nothing drastic on the speedometer, just the feel of acceleration when it picks back up. With the 3:73 gears, it was always in enough of a bind/strain @ 75 that it was smooth, but now since the engine is not under the load, it has a vibration when it coasts. I suspect now, this is where you guys say that you will have to go with the rear CV......... Help please. Anyone know of a way to fix this ?