1997 GMC Sierra 3500 4x4 SLE 6.5 V8 TD

[DarioGMC]

This is my GMC. Here in Italy there are several GMT400, but most of them are Chevy and 1500, some rare 2500 and, the few 3500s are dually. Mine is the first 3500 single rear wheel i've ever seen in Italy.
It's something almost unique.
When it was new it had been imported to Germany and stayed there until 2006 when had been imported to Italy. I'm the third owner since 2006.

You must be registered for see images attach

I bought it for a very low price because it was sold as "broken gearbox" and has some rust on the body.
You can drive it for 1-2 km...then it's like being in neutral, it can't move neither forward nor in reverse, but when it works it shifts every gear. So i think the problem could be a clogged oil filter.
Today the parts arrived from Germany, the fluids should arrive in a couple of days. I hope me and my brother will be able to work on the truck in the weekend...so we will see if we were right about the transmission. I hope it....i don't want to spend too much on this 4L80E, in the future i'd like to do a manual conversion. I'm not an automatic transmission fan.

I also bought oil and fuel filter, valve covers gaskets (there are leaks on both sides) and the serpentine belt that looks very old.

The truck has some engine mods :

an intercooler had been added, it seems something dedicated, not homemade ;

an afe cold air intake kit;

a couple of extra gauges (one says pyrometer and another one says manifold pressure)

the exhaust has a strange piece that seems something like a heat sink and the final part is a 100mm ( 4 inches) pipe.....the sound is awesome.

Who knows how many hp this thing could have?

They also added a button on the dashboard for the glow plugs. You can use them only manually, not turning the key....why? Maybe to save them when not needed in warm seasons?

I took some pics, could you help me to identify the mods?
Thank you in advance!!!

You must be registered for see images attach

I think the "pyrometer" gauge should be that wire that goes into the turbocharger and the "manifold pressure" should be the other one that goes into the intake manifold.

You must be registered for see images attach

The intercooler

You must be registered for see images attach

The strange exhaust part

You must be registered for see images attach

Another exhaust view : is it that pipe a stock part?


For this first post i think it's enough i don't want to bore you.

 

[DarioGMC]

And finally the GMC is alive!!!

We were right about the automatic transmission. We replaced oil and filter and the 4L80E is come back to life!
I want to say thank you to all the american people that uploded videos on youtube about doing this job, they helped us a lot.
I don't know how many years and kilometers that oil and filter had....everything was bad looking, and the oil had a terrible smell. I also don't uderstand if some idiot tried to close the pan or to stop leaks with some kind of sealant or if it is was just a destroyed gasket...

You must be registered for see images attach

But after a good clean, everything ok and ready to be reinstalled

You must be registered for see images attach

Then we also changed engine oil and filter....the filter was very old, the previous owner given me an oil filter because his mechanic hasn't been able to replace it.....i think that some ****** people don't be allowed to put their dirty hands on cars or trucks He also didn't replace the gasket on the drain plug in the pan...he putted some teflon on the thread!!!

We bought the new gasket and other five as spares......for 0,50 euros at the hardware store.

Anyway, we did everything but, after the short drive to test the transmission we noticed an oil leak from the oil filter relocator....you need a 35 mm socket to remove the oil filter relocator from the engine. We haven't one....and it's a strange size, not easy to find. But we are a mechanical shop....so we machined our socket.

You must be registered for see images attach

You must be registered for see images attach

And the final product :

You must be registered for see images attach

As you can see, we used the 30 mm socket as a support :

You must be registered for see images attach

We've been able to do the job without problems.

Once we had the relocator in our hands we immediatly understand why there were leaks......every o ring gasket was gone...so older that looked more like plastic than rubber. And also here, the idiots put their hands...they tried to stop the leaks with sealant

After a good clean, we went to the hardware store and bought all the new o ring gaskets. We bought more or less 10 for any and we spent 3 euros.....so don't buy the OEM kit for 15$.
The only one we did't find is the bigger one.......but we were lucky because it's exactly the same of my Bmw 525D E39 oil filter, and we have some as spares.


So another thing is fixed. There are still leaks frome the valve cover gaskets, i've just bought the parts, but i think i'll open a new thread for that job.....i have some doubts.

And i think we'll have to do a front end rebuilt...the drive feeling at the steering wheel is a bit vague...and the front tyres wears in an abnormal way....are more worn in the inner side.

 

[HotWheelsBurban]

Tire wear like this usually means ball joints and/or control arm bushings. I replaced the upper ball joints on my 99 C1500 Suburban 2 years ago; they were very floppy and had worn out the front tires in 6 months. I had to do a lot of brake repairs on the truck, and when I got it disassembled, saw the joints were very loose.
Good looking truck, sounds like you're making progress on it. Keep updating!
I like the socket you made. 35mm is equivalent to 1 3/8 inches; I think that size is also the front axle nut. Those are torqued to like 200 foot-pounds....had to replace the front hubs on my dad's 2006 GMC Yukon XL Denali which is all wheel drive. You may also need a short 6 point 15mm socket for the hub mounting bolts if the 400 series is the same as the 2000--2006 trucks. There's not really much room to work in there....

 

[DarioGMC]

Thank you so much for your advice HotWheelsBurban!!!

So we made a 1 3/8 inches socket.

I go crazy every time with those strange measures you have in the USA.....we had an American waterjet machine, in fact i have a series of wrenches in inches but i remember i always had to try three or four before keeping the right one Why don't use simple numbers like the metric ones? It's ways easier! Also my ex '95 YJ 4.0 H.O. had some inches bolts...

 

[Schurkey]

I go crazy every time with those strange measures you have in the USA.... ... i have a series of wrenches in inches but i remember i always had to try three or four before keeping the right one Why don't use simple numbers like the metric ones?.

Most "American" / SAE tools are measured in either 1/16 with a few by the 32nd of an inch.

What would make it complex for someone who doesn't work with it often is that the fractions are reduced as common practice. So 16/32 or 8/16 gets "1/2" stamped into it.

So a wrench set might go from 1/4" to 1 1/2"; if a person wanted to think in terms of numbers, that'd be 1/4=4/16, (4) 5/16 (5), 3/8=6/16, (6) 7/16 (7), 1/2=8/16 (8), and so forth so that 1 1/2 =24/16 (24).

Throwing a wrench (pun intended) into this system would be oddballs like the two 11/32 wrenches I have. So maybe you'd want to get used to thinking of them as the x/32 number.

Numerous tool manufacturers/vendors use the size in 32nds as part of the part number for the wrench. For example, a Snap-On 1/2" wrench will have "16" (16/32 = 1/2) somewhere in the part number.
SOEX16
OEX16B
BLPCW16B

 

[DarioGMC]

Wow, nice explanation Shurkey!!

Anyway, i still prefer metric system. I think it's ways better.
The good thing is that i discovered that this truck has a lot of metric bolts here and there


Restoration goes on. The steering box play was embarassing and also a bit dangerous, you had to do a lot of corrections to go straight.
I've found a good video on youtube and today afternoon me and my brother did the adjustment of the steering box play. Now it's far better

Then we also jacked the front wheels and there's a lot of play. The front end rebuild will be one of our next jobs.

 

[Schurkey]

Wow, nice explanation Shurkey!!

Easy--if a person pays attention to tool catalogs (and works in the SAE system instead of that damned Metric crap...

Restoration goes on. The steering box play was embarassing and also a bit dangerous, you had to do a lot of corrections to go straight.
I've found a good video on youtube and today afternoon me and my brother did the adjustment of the steering box play. Now it's far better

"The" adjustment?

There are TWO adjustments. Folks only do the simple one, but that's the SECOND one that needs to be dicked-with, AFTER doing the difficult one.

Then we also jacked the front wheels and there's a lot of play. The front end rebuild will be one of our next jobs.

Common as dirt. Don't forget the control arm bushings. I prefer Polyurethane. Not everyone agrees.

 

[skylark]

"The" adjustment?

There are TWO adjustments. Folks only do the simple one, but that's the SECOND one that needs to be dicked-with, AFTER doing the difficult one.


Also a very good way to screw up the gears on an otherwise good box.

 

[DarioGMC]

Schurkey : i often say "damned Americans and their fu****g inches!!" So for you metric stuff is the same

Now, after reading your comments, i have a doubt about what we did to the steering box, so i'll have to do some more search about it....anyway it goes better now.

About polyurethane i always read opposite opinions. Some people say it's the best, other say it's crap becase lasts few km\miles.


As written in the other thread, now we are in the process of replacing the valve covers gaskets.

 

[DarioGMC]

Finally the valve covers gaskets job is done!

We made some mistakes and had some trouble but, at the end everything went ok.

First we tightnened too less one line on the pump distributor so the happiness of hearing the engine run again lasted few seconds It leaked fuel like there's no tomorrow.
So, if you know how it's made, you know that to tight that fu****g bolt you have to pull out the intake manifold again.....

....we tight the bolt but when we reinstalled the manifold we accidentally bent the driver side manifold gasket But, fortunately the gasket didn't broke, so we've been able to bring it back to its original shape with a rubber hammer beating on a plain surface (milling machine table).
At this point we thought that everything was right....but it wasn't. There was a little oil leak from the passenger side cover : the two central bolts on external side that also support the fuel lines bracket weren't tighten enough.

Anyway, now it's all ok. We surely learn a lot and the satisfaction is priceless.

There was also an air leak from the upper side of the intake manifold that means boost loss. So we cut out our new gasket from a sheet of gasket paper.

Next job will be the front end.