4.11 gears

[craig]

Edit: I edited my previous post with a couple of other questions too.

Have you tried jacking it up and turning the wheel or are you assuming that you can't hear anything when it is at slow speeds? If you haven't tried, I'd encourage you to at least see if you can hear anything.

If you absolutely can't hear anything at low wheel rotation speeds then take it down to a shop, put it on a lift, and stand under the truck while someone hits the gas pedal. Use a hose if you need to locate exactly where the noise is coming from.

I just fixed a problem with absolutely identical symptoms last week. Whine at 35. When I jacked up a rear wheel it was a tapping sound that only turned into a whine as the taps got closer together in frequency.

In my case, I also replaced the diff which didn't work. I jacked up the truck to verify that it was still coming from the diff. It was, so I pulled the 3rd and put the new diff in a used low mileage carrier and bolted the whole thing back in. It was the cheapest way I could find to get things fixed.

Craig

 

[DiscoveryXD]

I wish I had a place to put the truck up on a lift and run it while I was in it. I took it to the dealership a while back and the tech they put in it wasn't even running it the way I told him to. I said accelerate the truck, then just let the truck coast so you float the drivetrain. He just kept accelerating and then taking his foot all the way off the gas so it was always under torque one way or the other...

 

[craig]

Put it on 4 jackstands in your driveway and get a buddy to listen with you. Just point the truck towards the street so you don't drive into the house if it falls off.

The only way you are going to fix your truck is to figure out exactly where the noise is coming from.

 

[Phillip Lehn]

interesting. After swapping my ratios to 4.11 I have a noise at 60km (40 m/h) but then its gone at 70km/h and the mob who fitted it have done many conversions. There is no noise at slower speeds. Does not matter what gear i am in either. The diff have been inspected afterwards. It has never got worst so it can blow up what ever it is. Then I will know what it is. It will fail when I am in the bush????? Phil

 

[MyR1isFun]

Put it on 4 jackstands in your driveway and get a buddy to listen with you. Just point the truck towards the street so you don't drive into the house if it falls off.

The only way you are going to fix your truck is to figure out exactly where the noise is coming from.

WOW!! That sounds scary. Guess it not bad if the tires are still mounted. Never thought of that as a viable option before. I just might try it for kicks and giggles sometime.

 

[flyfisher11]

Matt,

Do you know of a Dyno out your way? It would be good to put it on a dyno where there is friction on the tires while turning, plus the safety factor is there.

Good luck,

Mike

 

[craig]

WOW!! That sounds scary. Guess it not bad if the tires are still mounted. Never thought of that as a viable option before. I just might try it for kicks and giggles sometime.

Not really. Use 8 jack-stands if it intimidates you.

Craig

 

[DiscoveryXD]

well I think I'm going to go the route Dan said to go.... I'll take the driveshaft off and put the stock one on along with changing the pinion back to what it was. I had the 1/2" spacers in before, but what angle should the pinion be at? I know you want the angle of the output shaft on the t-case and the pinion to be parralel so the offest eachother, but how do you find the angle of the t-case end? put it on the flat part of the brake drum?

 

[craig]

Get a magnetic angle locator and stick it on to the e-brake drum, write down the value. Then, stick it to the flat spot on the bottom of the diff carrier and write that angle down. The difference between these two is what you are trying to minimize. E.g. you want the pinion angle and the rear output shaft of the TC (that the e-brake attaches to) to be parallel... hang on, I'll find a link for you to the tool.

Here you go. http://www.amazon.com/Johnson-Level-Tool-700-Magnetic/dp/B00004T807

 

[DiscoveryXD]

yeah, I thought the e brake drum would work fine. I've got an angle finder and that's what I used to get the new DC shaft setup with.

The new shaft is only 1* off and it still makes noise and that's what pisses me off...

I don't like to admit it, but I have never hated my truck so much as I have these past few months this has been going on. It's a never ending nightmare.

 

[craig]

Matt,

I understand that you are frustrated. I've felt the same way with my truck before, and then it is all fixed and you are driving down the road thinking about how sweet your truck is. Keep that day in mind.

Might be time to step back and think about what you know about the problem:

( => means "implies")

- Load related => Pinion
- Rear axle - Not sure exactly where
- Swapped diffs once (RD56 to RD128) => Not the diff
- Pinion angle is OK, driveshaft rebuilt/balanced => Not the driveshaft
- Only happens when the driveshaft is connected

When you sent it back to Bill to swap the diff he obviously put it in a new carrier (since the air line on the RD128 routes out to a different location). Did he swap your gears from one carrier to the other?

Can you get a video camera and record the noise? Then use Video MP3 extractor to pull the audio off?

Craig

 

[gmookher]

Was the pinion bearing ever replaced? Even new, there a shit load of play, the torque on the nut holding the flange on the pinion needs to TIGHT. any reason to suspect a flange? The fact that its speed specific suggests a rotational vibe/ anomaly

 

[craig]

Gem,

I'm not sure it is speed specific. All we really know is that speed is required to get it loud enough hear it in the drivers seat.

Craig

 

[DiscoveryXD]

The entire diff is brand new. Bill sent me a whole new diff with everything in it and I swapped the 1st one out and sent it back to him.

I think I'm going to change the driveshaft and pinion angle this afternoon and see where that gets me. If the noise is the same, then it must be something other than the drive shaft.

 

[gmookher]

XD,
Interestingly,
my 2004 has needed the front pinion bearing replaced and the rear TC output shaft bearing...so far. 65k miles....

Craig was able to tell it wasnt his shaft, and you seem pretty sure its not your diff, so that leaves TC and whatever is inbetween for you. For him, its looking like something on the 3rd...IMHO

 

[DiscoveryXD]

I don't think it's the T-case... The 1st diff progressively got worse as time went by. The noise is much more quite with this diff, but still there, so it's either the shaft, diff or something else, but not the t-case. The tcase wouldn't all of a sudden quite down with a new diff. and the noise is coming from the back, no question about it.

 

[Mongo]

did you check all your wheel bearings?

 

[gmookher]

I don't think it's the T-case... The 1st diff progressively got worse as time went by. The noise is much more quite with this diff, but still there, so it's either the shaft, diff or something else, but not the t-case. The tcase wouldn't all of a sudden quite down with a new diff. and the noise is coming from the back, no question about it.

Hmm, interesting. dII right? What shafts do you run? Maxi's from gbr or stock? If only hubs/bearing swap/diagnosis wasnt such a pain in the arse to do on a d2...I do envy owners d1 for that in a big way

 

[rmuller]

Hmm, interesting. dII right?

XDs are generally 1997 D1's... although i think there are some 96's..

 

[gmookher]

XDs are generally 1997 D1's... although i think there are some 96's..

shows what I know about d1's... thanks. In my head I was thinking "sd", which was available as a designation on both d1s and d2s..