I am playing around a bit tuning the truck in the signature. What I have found is that it is a very early 94 and seems to have some leftover 93 parts on it from the factory. I am trying to ID the turbo that is on it. When I started tuning the truck I ordered a TST kit for a #5 plate. There was no place to screw in the boost elbow in the side of the snail like the pictures showed. There was/is a little bit of rubber line between the AFC housing and the hard line that operates the waste gate, so I added the boost elbow there and it is doing its job. Do any of you know what this turbo really is or what it should be? The boost elbow is currently limiting boost to around 25 PSI and I would like to know how much I can turn the screw in the elbow to increase boost. The truck seams to run out of air above 2300 RPM as the EGTs go very high very fast.

Clutch Question:
I replaced the stock 235K mile clutch less than 2000 miles ago. The flywheel was blued and I had it resurfaced. I have the #5 plate mentioned above, and the specs on the site where I bought the clutch matched the power level of my truck. What I am up against is that when I am at about 1/2 throttle in 4th (direct) I believe I am hearing the clutch slip as I try to accelerate. I have about 700 lbs of traction ballast in the bed, but did not think that would be enough to cause me trouble. The sound is akin to marbles bouncing on a heavy steel plate. I am at a loss as to why this clutch would be slipping at part throttle unloaded. What else might I be hearing?

 

Your turbo is a Holset WH-1C most likely. It is functionally equivilant to the hx-35 on 95 and later trucks. the only 'real' difference being that the compressor housing is retained with a v-band clamp on the wh-1c whereas the compressor housing on an hx-35 is retained by a large snap ring. Your boost elbow is fine where you put it. Like the hx-35, the conmfort zone for the wh-1c is up to about 32psi, so tightening the boost elbow for a little more boost would be a good idea to keep temps down. just keep running it a little tighter and trying it untill you see about 30-32psi at full load.

As for the tranny, what you're hearing is the gears rattling around on the mainshaft. It will occur mostly in direct and under 1800rpms, but can be observed in other gears as well. In direct, there's no load on the gears-the input shaft is clutched to the mainshaft and with no side loading, the gears are free to rattle around. Pretty normal. I make an effort to not load the tranny to hard untill about 1750, mostly cause the noise bugs me
Hope this helps.

 

Thanks for the advice on the turbo and gears. Is there a reason that I only hear the scary noise from the transmission when stepping on it a bit? That's why I thought it was the clutch.

 

stepping on the accelerator or clutch?

 

The clutch slipping would be near peak torque, around 2200 rpm if it was going to slip. This would be visible in the tach with no change in road speed but a jump in rpm.

Also, for 5th gear (OD), I would not load the engine hard under 1500 Rpm either for fear of hammering off the 5th gear nut.

 

Stepping on accelerator - I will play with this a bit and see if the rpms jump when I hear the noise.

 

I played with this some last evening. The RPM's don't jump, but there really is a hateful noise. I think I'll stick with rolling into the throttle instead of stabbing it.
Also, thanks for the turbo info. I'll get after that elbow with the hex key and see what happens.

 

I have found that different clutches will pronounce the rattling much worse then others. There is always a chance of having a busted hub spring in the drive plate too. I had a 12" ceramic (valair) clutch that made it sound absolutley horrible, in most gears, after new bearings in the trans. It made me second guess my work. Then after burning that one out, upgraded to a 13" kev/ceramic valair, and there is only a bit of grumbling if the throttle is stabbed hard in direct gear.