Derek Marsh

Hey everybody, just bought a 1996 3500 4wd 5sp DRW ext cab truck that has 4.10 gears on 3/20 and have some question

Problems with the truck:
-Fuel gauge bottomed out, waiting on getting a wiring diagram so I can test it out.
-5th gear rattle, don't know what repair kit I am going to get.
-Steering slack (repaired)
-Engine will not heat up all the way, I guess. Goes to probably around 175, then falls to around 150 then does it all over again. I have never seen a engine cycle so much. I did pull the tstat to see if it was stuck open and it wasn't, although there was a little piece to debris behind the stat. Tested it a pot of water at around 200 and it opened, so I am alittle stumped on what is going on.

Suggestions:
-About anything above would be appreicated.
-And this truck has 4.10 gears. I will be using this truck to haul the play toys around, tractor, horses, ect. But at highway speeds this truck is turning alot of RPMs, @ 70 i think it was at around 2400 RPM. Truck's top speed is right at 85, which I will never need to do that, but I would think I would need to be around 1600 to 1800 rpm at 65 or 70 to get the best fuel mileage while towing and cruising. Currently the truck does 45 to 55 within that rpm range, which would be great if most my hauling was intown, but it's not.
What are my options, go with a taller gear or maybe a Under/Overdrive?

Thanks in advance,
Derek

infidel

http://www.cumminsforum.com/forum/94...mperature.html

marder

Just enjoy the 4:10's they are going to be great if you are going to tow alot. Otherwise you answered your own question. Two choices: swap them for 3:55's or add gear vender. I hear gear vender can burn up pretty easily. Just what I have read in a few posts.

The temp gauge cycle is normal. Id be worried if it wasn't doing that.

patdaly

What tires does she have? I believe stock is 215-85-16, you can go to 235-85-16 for about 2" more diameter, past that things get expensive, and I doubt you will pay for the cost of doing them, this assumes your truck is mechanically OK. Sweet spot is 1600-2000 RPMs, how fast are you running right at 2,000 RPMs?

macattack_ga

-Fuel gauge bottomed out, waiting on getting a wiring diagram so I can test it out.

Common. probably fuel level sending unit. drop tank or lift bed to replace. not an expensive part less than $80

MikeR

Early original T stats are (still) notorious for fluctuating, so many truck still have their factory originals. A revised T stat has been around for a long time now.

Fuel sender floats are crap and a common failure. Like macattack_ga said, easy $80 part form the dealer.

GV overdrive units are junk, they don't hold up long term to the banging toque of the diesel, eats em alive eventually. 235 tires get you about a 250rpm drop like the '00-'02 trucks were seeing.

Derek Marsh

Sorry i haven't replied any, been doing nothing but working and sleeping it feels like lately.

Since my post I bought another t stat and the temp cycling has stopped all together.
I haven't yet, dropped the fuel tank to fix the sending unit, trying to burn some fuel out of there first.
Also haven't done annything with the 5th gear but I have teh stuff to fix it, I jsut need time the pull the transfer case off and do it.
And I figured an OD was not practical so I am going to leave the gearing as is. I am running 235 85 on the truck, so when I was doing "70", I was actually probably doing around 75 or so.

Other than all that I put some new headlights on her and an alternator, but have found another problem.
It has happened twice now, so I know it isn't just bad luck.
Every time I hit a good size water puddle I will throw my belt. Got to really looking at it the second time and it looks like the belt is over one groove too far on the AC compressor. Fixed it, and it went right back over again. Only thing I can figure is it is belt tensioner letting it do this. I don't have a clue though.

patdaly

Tensioner is a good bet. As they age, they pull out of square.

They aren't terribly expensive.

Derek Marsh

Yeah, I figured it had to be it since it is the only thing not hard mounted. Replaced the belt this evening and I could see the ridges walking up on one another while it was running on the AC compressor. Parts store said they would have one by tommorrow afternoon.

Next up on the list will be trying to pin point where I am leaking oil from on the front half of the motor.

caper

depending on what fuel sender unit you have ya can fix it with a $.50 spring , I just did my 98 and it works like new again.

heres the link
http://www.cumminsforum.com/forum/98...under-1-a.html