hbom

First, Happy hollidays / New Years All. Thanks for looking ->

Truck in question: Australian 1995 4runner 3vze engine with automatic transmission A340H - Hilux SR5 Surf with right hand drive.

Here is the problem: there is a rattle / "box of marbles" noise (like lose gear rattle) coming from the underside of my truck The sound comes on deceleration, especially on a level or down hill surface under breaking. It sounds like loose gears rattling, or loose linkages.

Does anyone have experience with a similar noise? Did you fix it or ignore it until something broke?

Some history:
The transmission shifts fine. No problems between gears. The truck doesn't get all the power it should, but that might be engine flaws like vacuum leaks that I missed when rebuilding the engine. Also, the propeller shaft is well greased, and all U joints are tight.

Common suggested fix: Transfer Case linkage pivot
I have packed, and re-packed the grease in the transfer case linkage pivot point... twice. I exchanged the pivot point cylinder for a used junkyard one.
No luck. I still have the rattling sound.

Checked oils: Rear Differential good (LSX90 - equivelent to 75w-90 I was told). Transfer case (ATF Dacron III - I know Dax II is suggested, but Dax III is supposed to be an acceptable replacement). Transmission is topped up with Dax III (a bit too much, whoops). I haven't been able to check my front diff yet (I need an impact wrench to get to the check nut out because I have a 1/4 steel bash plate - and taking the plate out is a bigger job than I would like as I made it myself and have now warped it on rocks).

On checking the front Axles, I realize the front right axle (the short arm side of the front diff- does the front diff in the USA have the small side on the left?) seems a bit loose. I have a spare front differential which also seems to be somewhat loose on the front right side. So, I'm wondering:
Is a bit of play on the short side of the front diff to axle normal? Do I need to rebuild / replace some front diff parts?

Next Tests:
My next test will be to do a stall test to see if I am having torque converter issues. I will also be checking the flex plate to see if the bolts are tight.
I'm camping ( bashing my truck on rocks ) over new years, and will be working on it when I get back, provided it doesn't break. So, there is time to post me some advice, especially if something comes to mind at 3 am.

Cheers!

Bills86e

Suggest you get it up on a lift so to have a buddy start-run it while you - look - listen - use your stethoscope.


Bills86e

hbom

Thanks for the suggestion. Alas, I don't have a lift... or even a decent garage.

I think I may have found the problem: Front Differential. I can be a bit slow sometimes... This model doesn't have hub locks, so the front diff is always running. While taking the truck down the same roads where I can really hear the rattling, I've put the truck into 4H so that the car is running the front differential. This force on the front diff seems to have taken up some slack, so it stopped making the loose gear noise. I think it's probably the front right shaft into the ring gear. Luckily, I have a spare front differential sitting at my house, so I've got some parts to play with.

I'll let ya' know if that is the fix when I do repair after new years.