humboldtMUD

got noise from the front end, around 15mph and faster. sounds like a rattle grindy noise, offensive and loud but doesnt seem like anything is going to break. doesnt do it in full acceleration or deceleration but inbetween pretty bad.

thought a t case bearing was the culprit. got my new 4.7 inchworm t case and exact same noise. very pleased with the 4.7 tho.

anyone heard this before?

took drive shaft off and ripped around w/ the hubs in and no noise

have a tatton drive shaft non cv. all ujoints good. drive shaft angle is pretty maxed out, u joint doesnt hit yoke though. doesnt seem like seem like it could be drive shaft but....?

slightly frustrated anyone with some input on this would be nice.

xxxtreme22r

just to clarify, you said noise goes away without front driveshaft in and with hubs locked correct? is this with or without the t-case in 4WD.

humboldtMUD

yea didnt do it with tcase in 4x because i felt like being lazy and leaving the top part of the shaft on and tying it up. just cant accept that the new tcase makes the same noise

xxxtreme22r

ah forgot you had said did the same thing with both cases. I know you said the joints were good but maybe one of the u-joints don't like your driveline angle? (probably the one closest the t-case assuming your front pinion angle is good)

what year is this BTW. looks like 84-85 SA right?

humboldtMUD

its a 88 w/ tg sas about 4". i flipped the driveshaft around with no difference as well. this noise doesnt sound at all like it could be the drive shaft but logic would say it is. im planning on getting a high pinion up front to help with the angle, but i want to locate this problem before i drop some more $$

xxxtreme22r

do you think maybe the springs are "wrapping" on you and what your feeling is maybe a minor "wheelhop"

I think that's about as far as I am gonna be able to go, just thought I'd ask some other things to clear some stuff up for someone who "knows" SAS very well.

***** disregard that that would be a vibration not a rattle lol. ******

xxxtreme22r

whoa hold on a second, is there any remote possibility that the front gearset is a different ratio? kinda stupid question I know but the way some things have been going around here lately..... lol.

humboldtMUD

ha, well its 4:88 all round. front and rear have like 20,000 miles. thats whats pissing me off is everything is fairly new, if not brand new! i think im going to unbolt the rear driveshaft and put the front on blocks let her rip, lol well see if i can hear it without hurting myself

xxxtreme22r

hope you have really good jack stands. lol.

humboldtMUD

ill just use two hi lift jacks, think thats a good idea? haha

humboldtMUD

ok, so not much noise on the thread but i think ive come to some sort of conclusion.

noticed the transfer front flange is pointing towards the sky...not really but it shouldnt the front and rear flange be perpendicular to the axle flanges?
this explanes the bad vibes.
input here would be helpfull.

fyi i got bombproof motormounts from TG and the tranny mount looks just fine. the frame mount looks stock....

do i need to lower the engine..??

ill take pics if itd help

peow130

You might consider buying a low profile tranny skid plate to bring the tranny up as well as the ground clearance.
Dont change your tranny mount, or go solid, cuz you risk cracking the case.

If you can lower the mounts without any mods you might be able to get away with it.
Also, check the front pinion flange.
Is it loose?

humboldtMUD

nothing is loose

i think the "easiest" way of lowering the engine would be to cut the frame mount and reweld to appropriate position. does sound like a bit of a pita.

inchworms xmember can move the transfer wherever i want. but i think if i moved the tranny up id HAVE to get high pinion anyway. seems the right thing to do though

4Crawler

iTrader: (3)

From the factory, the flanges are not vertical, the rear tips down a few degrees, front up the same angle. Might check your driveshaft alignment and phasing:
- http://www.4crawler.com/4x4/CheapTri...n-Measurements
- http://www.4crawler.com/4x4/CheapTri....shtml#Phasing

And it might be that the rear shaft angle is just too steep to run smooth. Mine did this when I hit something in the 12-15 degree range. Swapped to a CV type shaft in the rear and it was a lot smoother.

humboldtMUD

thanks for the link, i remember reading this a while back. lots of good info. rear is perfect, not cv either. im going to read up on that link, thanks again

humboldtMUD

by the way i learned about phasing the hard way some time ago, quite important indeed