Problems with new gears

[Joe 1320]

I guess the synthetic fluid and the limited slip additive don't work together very well.

I run synthetic and GM LSD additive with no problems.

[jerrysta]

I finally got to test my reprogram.....everything that was reprogrammed worked well. Speedo is fixed. Shift points are fixed. I can accelerate past my prior shut off MPH.

Holy cow does the car shake though?!?!

The higher the speed the worse the shake. The shaking is also accompanied by a howling noise that sounds like it is the tires. I've never heard such loud tires before! It seems to go in and out in time with the revolution of the tires. They were just balanced recently. I don't know what to do now.

I do have the ES poly tranny mount and I understand there were complaints with vibrations with this tranny mount. I don't know if that could be part of the problem.

[Joe 1320]

Driveshaft...................there was a TSB on the stock sttel shaft being out of balance. The factory fix was to swap the aluminum 1 LE shaft. Most times it was barely noticable until you swap gears. Then the additional rotation speed amplifies the condition.

[jerrysta]

Is there any advantage to the aftermarket driveshafts or should I just pick up an LS1 aluminum driveshaft?

[93/96 f-body]

related

What about your vibration at 85 did it go away also?Or did you rebalance your tires yet?

[Joe 1320]

Is there any advantage to the aftermarket driveshafts or should I just pick up an LS1 aluminum driveshaft?

Alot depends on your intended useage. The LS1 driveshaft isn't quite as strong as the 1LE for the LT-1. There are many other aftermarket shafts too. Automatic trans cars are a little less abusive on parts too. If you are under 350 rwhp, either should be safe.

[Eric 97LT4SS]

When I changed my fluid last summer I used two bottle of GM Limited Slip Lube and the required amount of Valvoline 75w-90 Synthetic Oil. Will the GM lube damage anything since I mixed it with the Synthetic? Thanks

[fastTa]

I took the gears back a few times and we added some more limited slip additive but it kept making the binding noise on the turns at slow speeds. Finally he decided to pop the cover and see if there was anything wrong inside. He refilled it with normal differential fluid (instead of the sythetic which is what he put in there the first time) and added the limited slip additive to it. Anyway, it fixed the problem. No more grinding, binding, rubbing, and whining noises when turning and only a small whine at 45 mph but very unnoticable. I guess the synthetic fluid and the limited slip additive don't work together very well.

Generally speaking yes, synthetic gear lube does not cooperate with the required limited slip aditive for our GM 10 bolts. Some people report having no problems though. Not the case with me however.

I tried to use synththtic with the GM limited slip additive and it was horrible. Drained it and refilled with conventional Mobil 1 gear lube and ithe limited slip aditive and immediately fixed the problem.

[jerrysta]

Right now I am under that HP but I am getting a N2O kit installed real soon. I'd rather not bust anything by skimping now. I guess the prices on them surprised me a bit.

Even with N2O I am not making near that HP, but I always try to buy with the idea that I may make more mods in the future.

[fastTa]

Right now I am under that HP but I am getting a N2O kit installed real soon. I'd rather not bust anything by skimping now. I guess the prices on them surprised me a bit.

Even with N2O I am not making near that HP, but I always try to buy with the idea that I may make more mods in the future.

You can get a fully assembled Strange chrome-moly driveshaft complete with 1350 spicer heavy duty u-joints for only $198. Doesn't get much cheaper than that for a high quality DS. The seamless driveshaft is still only $275.

[Eric 97LT4SS]

fastTA what problems did you experience with the GM Additive and Synthetic fluids mixed together? Probably about 500 miles since I changed to the combined fluids and no problems yet!! Thanks

I installed LPE's 3.5" Aluminum driveshaft over the winter, on Sale for $225 at the time I think. Haven't had the car out yet so not sure if my minimal 4.10 gear whine has been reduced.

http://www.lingenfelter.com/Merchant...egory_Code=P08

[fastTa]

fastTA what problems did you experience with the GM Additive and Synthetic fluids mixed together? Probably about 500 miles since I changed to the combined fluids and no problems yet!! Thanks

I installed LPE's 3.5" Aluminum driveshaft over the winter, on Sale for $225 at the time I think. Haven't had the car out yet so not sure if my minimal 4.10 gear whine has been reduced.

http://www.lingenfelter.com/Merchant...egory_Code=P08

Major posi-trac clutch slippage. It was really pronounced when cornering hard. Coming out of the apex of the turn and attempting to throttle steer out, it would feel like I shifted into neutral all of the sudden and instantly bang of the limiter. Not good.

I spoke to Eaton and Auburn and they said their clutches were absolutely not designed to work with synthetics. They both use a bonding agent to attach the carbon-fiber clutches to their respective discs and that bonding agent WILL deteriorate with the majority of aftermarket synthetic gear lubes. Even if the clutches don't actually detach from the dicss, they will still loosen over time and cause slippage.

So I took their advice and went back to conventional gear lube and the problem was instantly fixed and never occured again.

Even when you receive a new Moser or Strange 12 bolt posi, they include a flyer inside that says in bold words, "DO NOT USE SYNTHETIC!".

[jerrysta]

I don't know what seamless or non-seamless means. Will I just have to buy the driveshaft for 200 bucks and bolt it in or do I need other parts?

Sorry to ask stupid questions but I am very much a novice. This is my first performance car and I'm learning on the fly here!

[fastTa]

I don't know what seamless or non-seamless means. Will I just have to buy the driveshaft for 200 bucks and bolt it in or do I need other parts?

Sorry to ask stupid questions but I am very much a novice. This is my first performance car and I'm learning on the fly here!

Most OEM type driveshafts use a process called C.R.E.W.(cold rolled electric welded. This is a process in which the tubing used for the driveshaft is constructed from taking flat sheets of steel, running it through a series of rollers to form a tubular shape, and then electric welding the seam.

Then you have D.O.M.(drawn over mandrel) type driveshafts. This type of driveshaft tubing is basically made the same way as a C.R.E.W. type shaft with the additional step of drawing the tube over a die or mandrel. This step is a lot like a cold forging process which serves to make the tube much straighter, rounder, stress relieved and stronger. Although it appears to be, D.O.M. tube is not a true seamless tube. Seamless tube is generally made in very heavy wall thickness' and is usually used for hydraulic applications.

Then you have the true seamless chrome-moly and aluminum driveshafts which are drawn as a one piece true tubular shaft. It does not originate as a piece of flat metal and then formed into a tube and then welded. It is a solid tube with a much thicker wall. Seamless driveshafts are obviously stronger since they do not share the inherant weaknesses of the CREW and DOM type shafts. Seamless driveshafts are better balanced and do not reach critical speeds anywhere near that of a CREW or DOM shaft.

[93/96 f-body]

question

What about the problem you had at 85mph did that also go away?