When coasting at high speeds, doubler makes gear noises---UPDATE W/ PICS---

[dawson444]

----------UPDATE---------------
http://community.webshots.com/album/157702692oeRbuw

Those are pictures of the shaft, what do ya'll think?
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I looked at the angles, they look ok, here are some pictures

I have a doubler in my truck behind a TH400. When I am on the gas everything is fine, and when i am at low speeds I am fine. When I get up to high speeds (around 50-60MPH, my speedo doesn't work) and I let off the gas and I am coasting my doubler makes some bad noises in the gears. As soon as I start to accelerate again it goes away. What could this be? Thanks!

 

[Stephen]

Re: When coasting at high speeds, doubler makes bad gear noises, please help!

The first thing I'd check is the rear driveshaft angles. We've solved these problems with the application of a CV driveshaft before so that's a good suspect.
Do you get the noise in 4wd and 2wd? How about with the 205 in low or the 203 in low? I realize you may not get the same road speed in one of the low ranges but that would help troubleshoot where the sound is coming from.

The fact that it's only at higher speeds and under coasting indicates to me that it could be driveshaft related. A minor vibration from the shaft would be damped out under power if the gears were all being pushed into mesh but when you're coasting they're not forced together and they could be rattling in the backlash clearance.

Try some of this out and post up what you find, we'll keep working on it. If it gets critical, call up and we'll try to sort it out, that might work faster.