Suzuki Forums banner

1 - 3 of 3 Posts

·
Registered
Joined
·
32 Posts
Discussion Starter #1 (Edited)
My '87 w/ 160k has a whine that is speed/torque related. The faster I drive, regardless of gear, the louder it is. The more torque (throttle) at any speed, the more the noise.

Essentially ZERO whine under 35mph in any gear or throttle setting. From there it gets worse.

Noise at 35mph accelerating in 4th/5th gear Low Range (F hubs disengaged) is the same as 3rd/4th/5th gear High Range at 35mph.

There is some (10% maybe) whine on deceleration/coast compared to pull.

I was SURE it was the differential, so I installed a 3rd member from a junked Zuk in the rear which had ZERO wear-the teeth were not even shiny, but looked Parkerized. I changed out the side-gears and set backlash at 0.004" and just a tad (maybe 0.002 side free-play) on the differential cage. The original differential gears showed some wear and surface corrosion (from internal condensation sitting w/out being used for a long time after oil drained from the top half of the ring gear) on many ring-gear teeth, so I had hope I'd found the cause, but the noise is the same.

The noise is 100% speed related and load related. No noise at zero torque (not accelerating- just decelerating slightly so the engine is doing nothing).

No noise in neutral coasting (gears completely unloaded), though in neutral at idle w/ clutch released there is some input shaft bearing noise that pressing the clutch causes to disappear completely after the input shaft stops turning.

The overall noise level at 45mph is annoying w/ no carpets and the top off, but hasn't changed in the 1000mi I've had the vehicle. With the the top up it's really annoying.

I disassembled the car and painted it in pieces and re-assembled it, rebuilt the engine completely, and now re-did the rear differential, so...

I really don't want to rebuild the wrong box first if I can help it. What's your best guess based on symptoms?

The car is 100% rust-free (not even surface rust on fasteners under-chassis), so it's a good example, and I want it "right," but I'm getting tired and lazy.

Thanks,
Bob
 

·
Registered
Joined
·
264 Posts
What's your best guess based on symptoms?

Bob
My best guess would by the transfer case. In particular the needle bearings on the intermediate shaft and gears. The other item could be worn thrust washers letting the gears shift and not mesh in an ideal pattern.
I should have replaced them (bearings/shaft) on my last TC rebuild, but got in a hurry and didn't. The bearings looked fair and the shaft had some pits. The shaft and needle bearings were the only bearings I didn't replace. My visiting in-law, who is a machinist for NA Rockwell, said "yeah, they'll make noise, but should last a while".
I thought I would replace that TC with another lower geared case by now, but 7000 miles later, It hasn't happened.
The whine is noticeable, but not too loud.
The transmissions are very east to rebuild. No special tools needed and no bearing preloads to deal with on reassembly.
The TCs are a little more difficult. Most all the rebuild kits are incomplete and the shafts need to be shimmed to get the correct end plays. The needle bearings, intermediate shaft and thrust washers don't come as a part of any of the $80 rebuild kits.
I cut my own shims from my selection of SS sheet stock, which saved a few bucks.
 

·
Registered
Joined
·
32 Posts
Discussion Starter #3
Do they usually just get noisier, or do they hand-grenade at some point?

I don't "feel" anything through either gearshift lever. Wonder if drilling holes and using a stethoscope through the transmission/floor (isolated from the tub by rubber grommets) would be instructive?

The TC is obviously easier to remove, but more difficult to rebuild.

Of course I had the tranny OUT when I did the engine, and SHOULD have rebuilt it then and there. Doh!
 
1 - 3 of 3 Posts
Top