Engine/Transmission (1994 - 1998) Light Grinding Noise

[KBurgoyne]

95 3500 with NV 4500 198000 miles. Above 30mph there is a grinding noise. It usually starts as soon as I get into 4th and continues on into 5th. Gear doesn't seem to make a difference though. The noise stays constant in or out of gear with or without the clutch in as long as it over 30. Even rolling down hill up to speed without shifting at all as soon as it hits 30 the noise starts, and stays constant until its back under 30.

Ive been replacing parts to get rid of it and no luck. So far the front rotors, pads, wheel hub bearing, U-joints, fan pulley, alternator, water pump, Power steering pump and steering box, and rear shoes. Fan hub bearing checked and given the OK at the shop.

The only possible suspects left that I can think of are the driveshaft or a trans bearing. Any other advice would be appreciated im running out of ideas and its driving me crazy(er)

 

[GAmes]

Have you tried putting it on a lft and running the engine to 30+mph? My first thought, btw, was the driveshaft support bearing.

 

[JMcCoy]

x2 on checking the carrier bearing. You could check that on the ground by grabbing the drive shaft at the carrier and shaking it. There should be no bearing play. The bearing is set in rubber so it will move like a motor mount. You could also try injecting grease into it with a grease gun needle. I do this every so often. Keep us posted on your findings.

 

[KBurgoyne]

definitely movement in the carrier bearing. Its on the chopping block. Thanks folks, I'll let you know if that gets rid of it. Side question, Im considering 3.31 gears. With the 4.10 and 5spd it tops at 75, and I don't bother with first since it screams at 10. Any thoughts on brand, price, maybe too much strain on the gears with the duals. I have nothing to tow, 90% of the time it just goes from point A to point B.

 

[hsmith]

I just did the rear brakes on mine and found the outer wheel bearings shot. I had no clue they were bad before.

 

[NIsaacs]

Side question, Im considering 3.31 gears.

If you have a 4x4 I don't think that ratio is available for the D-60 front, 3.55 is. Use OEM Dana gear sets.

Nick

 

[KBurgoyne]

its 2x4. the 3.31 with a manual is the same rpm wise as a 3.54 with auto.

 

[NIsaacs]

its 2x4. the 3.31 with a manual is the same rpm wise as a 3.54 with auto.

Okay, that should be a good choice, especially if you are running the stock tire size, they are kinda small.

Nick

 

[KBurgoyne]

well the old drive shaft bearing is gone, but the noise isnt. any other suspicions.

 

[KBurgoyne]

Well the truck is currently down as at the shop having the transmission looked at. I took the floor cover off and drove around for a better listen, and it sounded like the trans. Hopefully I wont have a big crooked number thrown my way. Anyone have a built one that they love for a decent price.
http://www.xtremediesel.com/atsbuiltnv4500transmission.aspx

 

[DonFitzwater]

That's the sound of your wallet flattening out! I'd get an updated trans from Standard Transmission if I needed one.

 

[KBurgoyne]

for ring and pinions what is the reason for the price differences. One 3.31 is 250 and one is 650.
http://www.xtremediesel.com/differentialcovers_1.aspx

 

[KBurgoyne]

Ouch

got some bad news. Worn bearings and syncros in the transmission rebuild is under way and will be around 1500. Clutch is also worn out and is being replaced with a south bend plus new hydrolics total will be just under 4000 most likely, but it will be a better than new trans. Still hurts though #@$%!

 

[JMcCoy]

Sorry to hear about your transmission. I don't know why some manufacturers charge extremely different prices for different different ratios. Maybe supply/demand. Just don't go cheap. I would stick with Spicer and maybe Yukon. You can often find new stuff on ebay for cheap.