53bowtie

iTrader: (6)

Hey guys I am in need of some help. I just installed some 3.73 gears out of a 2001 4wd into my 2002 2wd. Now there is a noise only when I am coasting. The noise is kind of a clunk noise and it sounds like it happens once per revolution of the wheels. The best I can describe it is it sounds like a train going over the couplings of the track rails. I double checked all the gear install and could find nothing wrong, no slack in anything. My dad said it was more noticable in the drivers side axle and sometimes when I would let off the gas to coast the left axle would momentarily stop and then start again (truck on jackstands not going down the road). This made me think it was something with the clutch disks in the factory posi. Anybody have any clue what this could be??

One last question. I obviously need to recalibrate my speedo now since the gear change. Do you guys think I would gain anything from a tune since my truck is basically stock and has no mods planned for it in the near future? Or should I just get the speedo recalibrated and call it good? I guess it would be a difference of about $150 so I wanted to know your guys thoughts before I went either way. Thanks in advance.

1LOW4X4

iTrader: (2)

Dude, I'm having the same exact problem! I blew my g80 up and installed another 3:73 carrier in there, but left facto ring and pinion. I am having the same exact noise, clanking when I coast.

I put it on the lift with silver-mod-o and let him listen while I revved it up about 60 mph and let it coast....he swears it's the pinion gear.

Hope you figure it out, I'm bout ready to get a trutrac with all the extras and just be done with it

53bowtie

iTrader: (6)

Yeah I was thinking when you rotate the pinion back and forth with the slack in it that it kinda sounds like that. My dad thought he could feel it more in the drivers axle tube than the pass though so I thought maybe something to do with the posi. But the fact it only happens when I coast kinda makes me think its the gears.

I just kinda wanted to know others opinions about it before I droped $500 for a tru-trac not knowing if that would fix it or not. I may take it to a buddies shop and go over all the settings on the gears again. If they all look good then I have no clue. Let me know if the tru trac fixes it, that may be the way I have to go. Just wasnt expecting a $100 gear change to turn into $500 lol.

Anybody else have any input??

iamkeniff

iTrader: (16)

you didnt see any chunks/cracks in the ring and pinion right? did you replace the bearings? you didnt set your pinion bearing too tight did you (thatd give you a hmmmm'ing noise if its going out actually)
did you mark which side the shim goes on? if it has too much backlash itll clunk i think.
a Tru-Trac will be a great upgrade either way lol
get a custom tune it's worth it imho.

53bowtie

iTrader: (6)

I didnt see any cracks in the ring and pinion although I didnt look real hard for them. I replaced the inner pinion bearing but not the outer because it looked fine.

I did tighten it a bit tighter than before because of the new bearing but the noise I am hearing is a distinct "clunking" noise. It almost sounds like a roller coaster ratcheting up the first incline.....kinda a clunck clunck, clunck with the speed of the tires. And like I said earlier it is only when I coast which makes me think its in the gear setup but this does not sound like a gear "noise" to me.

I marked which side the shimms went on for the carrier bearings, the pinion only had one shim. I am at a loss. I really dont want to spend $500 for a tru trac and the problem be in the gears because then a tru trac wouldnt fix the noise. I wish I could narrow it down farther. I think the only thing left to do is check all the readings on the gear setup again and see if there is something I missed.

53bowtie

iTrader: (6)

Anybody else have any ideas about this?

53bowtie

iTrader: (6)

Bump. Anybody have any other suggestions??? I would really like to figure out what this noise is this weekend. If you have any other ideas to check I would greatly appreciate it!! Thanks for all the help thus far!

fredkj3

iTrader: (1)

check your U joints they could have some slack in them... disconnect U joint and check slack in YOKE

2ToeRacing

+1 for the u joints.You night have to recheck your shim work on the gears.When you have a whine on the cost side it means that you need to re shim but I couldn't tell you in what direction.

Truckshop

iTrader: (17)

you said you replaced the inner bearing. did you replace the race with it? there was a design change at some point.