88GMCtruck's 98 Silverado Towpig Build: "Black Fox"

[88gmctruck]

I haven't full decided what i'm doing with the grille & lighting. Planning on a GMC grille (probably junkyard). Headlights wither TYC or find adjusters to run my quad bosch H4 lights.....

 

[88gmctruck]

A few dollars in parts here..... 3 transmissions and 2 transfercases....

Here is what came out of my truck....

 

[GM Guy]

I am beaming with happiness knowing you got a Manual transmission.

only way it would be perfect is if it was a 6.5L and a 2wd and gloss white!

good luck with it!

btw, dont rule out another 6.5L in the future, I cleaned the crap out of my radiator on my 95 GMC and with the 6 blade fan and low output water pump, I can pull 18K and stay under 210 on a 100 degree day, no AC though. imagine what it could do with a HO pump and a duramax fan! :O

 

[88gmctruck]

Hahahah well a 2wd truck isn't a good option for me. I would actually prefer white though.

I wouldn't want another 6.5L for towing. The way I tow, even when I had my 99 (which is HO pump and 9 blade fan from the factory) would easily push past the 210 mark. I will do my best to keep the speed limit up hills and the mountain pass. I couldn't do that without risking heat damage to the diesel where my 454 doesn't even flinch.

I wouldn't mind another 6.5L for a commuter though.

 

[DieselSlug]

Nice find, that is almost impossible to find a truck in that condition around here.

Be funny to have some southern guys work on my truck, id like to see the looks on their faces at whats hidden underneath rot wise.

 

[88gmctruck]

Woof!

A few parts started to show up.

What have we here? Combine this with the 2 I kept from my 99 K2500.....

All the moving parts of the NV4500 other than gears and shafts....

 

[88gmctruck]

Came home to this today... Love amazon's 2-day shipping.

U-joints, Carrier Bearing, and some trailer wiring.

Got the joints installed. Going to bring the carrier bearing to my dad's tomorrow and press the old one off and new on.

Suburban rear Weathertech mat. I stole the front weathertech mats from the 88 also... It fits ok, not as close to the rear seat frame as I would like, but better than a universal mat for sure.

New clutch kit.

Compared to the old clutch disc.... It's a little different and a heck of a lot lighter. I'm not quite sure how I feel about it. Seems wimpy.

For comparison... Here is the Hays supertruck that I installed in my 88 about 4 years ago. It's a GREAT clutch. I'm thinking I should swap this AC Delco one out for this instead.... Thoughts?

 

[ak diesel driver]

the Hays disc appears to have quite abit more friction material, as in surface area. is that so?

 

[btfarm]

Pretty dramatic difference in clutches. I've always bought the best clutch setup I could get at the time as long as I had to go that far.

 

[88gmctruck]

the Hays disc appears to have quite abit more friction material, as in surface area. is that so?

Correct.

Pretty dramatic difference in clutches. I've always bought the best clutch setup I could get at the time as long as I had to go that far.

That is what i'm thinking then again this is the OE replacement which hold up fine too. I'm thinking I'll just run this stock one. I can pull the transmission in about 2 hours anyway.

 

[88gmctruck]

Started tearing into the transmission yesterday. I pulled it and didn't REALLY look at it as it sat in the garage this week.

Top cover off.

Peeking around. Notice the metal shavings. Welp, 5th gear was backing off and the nut wasn't tight...

Drained what was left of the fluid.... This color isn't good.

5th exposed. It's walked back but hasn't contacted the reverse shift arm, no damage.

Popped out the input shaft. I was quite loose and because the pilot bearing had long failed and chewed it up, it was to be replaced anyway. Here is the nose of the mainshaft... Where the input rides on a needle bearing on it...

Damn. This is a showstopper. Planned to have this back together and on the road this weekend. At least I know where the metal was all from now.

Determined that I can still pull the shafts and rebuild the countershaft.

Mainshaft pulled

Countershaft in the housing....

Empty shell.

Counter shaft removed.

Countershaft re-installed with new bearings.

New input shaft

Oh yeah, this wouldn't be possible without this tool set....

Once that was done I set about working on a few other things, such as cleaning my transfercase up.

And my friend (who's also working on his transmission) painted all our drivelines up after I re-built all the u-joints.

And a few more parts to add to the pile.
Throwout bearing/Slave Cylinder.

Tow mirror parts. My current set has a bad heated glass on the driver's side and is missing the post cover on the passenger's side. A friend of mine had his truck stolen and the pass mirror glass was shattered. He ended up replacing the mirrors with a new set and I picked these up off him for parts. Driver's mirror is 100% good. Passenger is for parts only.

Now that I have to buy a mainshaft, I'm at standstill on the transmission itself for a few days. figured I can get some other things taken care of in that time, like the trailer harness, other fluids, mirrors, etc.

 

[btfarm]

Nice post Dave. That trans saw some serious abuse at some point or was run dry/hot. Pilot bearings are a big culprit for a failed high gear. Seen it my share of times back when most trucks were manual.

 

[THEFERMANATOR]

Looks like the wrong oil was used. Many think syncromesh is compatible, but it is not. You need to run a GL-4 of an 80W90 viscosity and is a full synthetic with modifiers for cold performance.

 

[tanman_2006]

Looks like the wrong oil was used. Many think syncromesh is compatible, but it is not. You need to run a GL-4 of an 80W90 viscosity and is a full synthetic with modifiers for cold performance.

That's alot of the same wear that was on my 94, the main shaft was ok but the bearings were crap and you could see discoloration from heat, pitting was next. The local machine shop polished it up and it looked alot better.

Source Unknown

 

[Burning oil]

Are you using the Dodge input shaft? IIRC its a direct replacment and is stronger. Not sure, but might be a good mod. Seem to remember that being a common mod when doing a Cummins convertion.

 

[88gmctruck]

Nice post Dave. That trans saw some serious abuse at some point or was run dry/hot. Pilot bearings are a big culprit for a failed high gear. Seen it my share of times back when most trucks were manual.

Well I know this truck had a camper on it, by the looks of it for a good part of its life. I'm thinking it was probably a combination of age, heavy loads, and incorrect fluid.

Looks like the wrong oil was used. Many think syncromesh is compatible, but it is not. You need to run a GL-4 of an 80W90 viscosity and is a full synthetic with modifiers for cold performance.

The ONLY fluid that should be in a NV4500 is the GM/Chrysler Castrol Syntorque. It is a GL-4 but is 75W90 viscosity full synthetic. It's a dealer only item, other than a few transmission places that have bought large quantities of it. I've ran the amsoil rated equivalent and it doesn't perform near as well as the Castrol stuff does. From what I've been told and have read, the factory stuff is a specific blend that off the shelf fluids do not have to protect the syncros.

That's alot of the same wear that was on my 94, the main shaft was ok but the bearings were crap and you could see discoloration from heat, pitting was next. The local machine shop polished it up and it looked alot better.

Source Unknown

My countershaft and rear main bearing looked fine, but the wear on the input and it's bearings is what did it in.

Are you using the Dodge input shaft? IIRC its a direct replacment and is stronger. Not sure, but might be a good mod. Seem to remember that being a common mod when doing a Cummins convertion.

Chevy and Dodge input shafts are different to my knowledge.

 

[THEFERMANATOR]

Are you using the Dodge input shaft? IIRC its a direct replacment and is stronger. Not sure, but might be a good mod. Seem to remember that being a common mod when doing a Cummins convertion.

It's an easy mod when doing a CUMMINS swap as you need the different input for the CUMMINS clutch to work. it is stronger, but I don't think it will work with the GM clutch and bellhousing.

 

[83GMCK2500]

Oh yeah, this wouldn't be possible without this tool set....

Now I see what you've been busy working on. So, when can I bring my 4500 over for a rebuild?

 

[GM Guy]

IIRC starting in 96, but it may have been later, GM went to a bigger input shaft on the C3500HD chassis cab, so a guy can run a HD input and clutch and get the big input that way.

you are coming along way quicker than I can even comprehend, stuff is done in days and weeks around here (occasionally months and years :O )

 

[Burning oil]

Chevy and Dodge input shafts are different to my knowledge.

Your probably right, I dont remember. It was something like if you are swaping trans from one to another you would need the input shaft from one (dont remember sorry)