The clunk thing

[MoonRaker]

Ok, ive read most of the clunk catagorys but I dont think ive found any answers. I was having a clunking problem before when id make sharp turns. I shifted the transfer case to 4 low and pulled the E brake as hard as posible. I had someone get in my VX and told him to shift from foward to reverse. Holy crap, the front diff moved about 3 to 4 inches on the mounts, thats not rite at all. I pulled the front diff to check the mounts and they were fine, a buddy of mine told me to make some urathane shims because the mounts might be week from age, abuse and that fixed the problem. It worked well till about a month ago. Now when I lay on the brakes to make a stop then let off the brakes I feel and hear a major clunk and its not gear lash. It sounds like a major shift of a componant. I cant get it to act up on a lift either and I checked that all the bolts were tight. Im about to rebuild my transfer case bacause of leaking seals. Anyone think it could be that the chain in the transfercase has been over stretched or is there any other ideas. The truck runs strait and feels very tight and smooth considering the abuse ive put it through. It used to start shaking a little at 75 but after the shims were inplace it drives smooth as silk to 100 plus. I wish I would have done that before I drove crosscountry. Ive noticed alot of the same style mounts on alot of the moving suspension parts and im thinking of shimming them all.

[etlsport]

my VX has always done that clunk after very hard braking, just figured it was normal. i prepare for it now, when i come to a hard stop i just shift to neutral for a second to relieve the tension

[nocturnalVX]

My VX would clunk if I didn't come to a complete stop and then hit the gas. The transmission had a slight leak and it was slipping. Maybe that's what is going on?

[MoonRaker]

Na, tranny is tits. Ive checked the fluid when I changed, no band crap.

[MoonRaker]

my VX has always done that clunk after very hard braking, just figured it was normal. i prepare for it now, when i come to a hard stop i just shift to neutral for a second to relieve the tension

Im pretty sure its not normal, atleast on mine. Im woundering if it has to do with the rubber mounts in the A arms. Maybe you load them under hard braking and when you release them they become unsprung causing the clunk. Another thought is like I said before about the transfercase chain having slack. There does seem to be alot of backlash in the drive shaft entering the transfercase. If the rebuild for the transfer case costs 1100 in part, I wounder how much it would cost to put fresh gears, bearings and seals in the front and rear diff, couldnt be that bad. Im trying to keep this truck alive for atleast another 100,000 miles if not more.

[etlsport]

not sure what could be cuasing it but its a similar feeling to when i start the vx and put it into drive while the e-brake is still pulled. the vx doesnt actually move but it feels like its raising

[tom4bren]

"not sure what could be cuasing it but its a similar feeling to when i start the vx and put it into drive while the e-brake is still pulled. the vx doesnt actually move but it feels like its raising"

That's axel wrap & it's normal.

[Deigo]

i was going to ask about the clunk too. when im in low and shifting between drive and reverse there is a cluck and jerk. i twisted the drive shaft by hand and there is about a quarter inch of play, so i assume the clunk is the drive shaft twisting free before catching and that low range amplifies the jerk by applying more force( torque ). i was thinking worn u joints, but could you explain axle wrap as this may be the problem.

[WILLY]

Well i too have the sprung energy thing after releasing the brakes and i have thought it might b the brake callipers,my callipers although securely bolted on have a small amount of play in them when grabbing them and jerking front to back so i thought they might be being drivin forward when braking to a stop and then when the brake is released they spring back, idunno just a thought.

[tom4bren]

I guess I used the term axel wrap too generally. When your vehicle 'stands up' with the parking brake applied, the same forces are at work, just not to the same extent.

"Wrap-up - Referred to as both rear spring and rear axle wrap-up. As power is applied, torque load causes the rear pinion to pivot upward. Once this load reaches a certain point the leaf springs begin to deform, which stresses numerous driveline components. The "fix" is to increase spring strength, via add-a-leafs, or install traction bars."

I know that this definition is for leaf springs but similar effects will be in play with coil springs. Remember when Kicker shocks, sub frames & ladder bars were the 'all the rage' with agressively lifted trucks? Those were all cures for axel wrap (wheel hop) just like steering stabalizers were supposed to stop 'bump steer'.

[Solitude]

There is a TSB that says the clunking is normal.. Mine has clunked since it was brand new

[MoonRaker]

Well, theres all kinds of stuff that can clunk. Its the how bad is it or is it getting worse that you need to keep an eye on. If you run the the VX hard, things are going to wear alot quicker. I think im going to start buy making more of the shims I mentioned before and do part buy part while testing in between. Im still waiting for the clutch pack wich is on back order from isuzu. Id recomend that the guys that own one and plan on keeping it on the road withought a long wait start collecting parts. Were lucky that the tranny parts are readily available since its a common tranny but what about diff parts. Has anyone looked into diff parts? I havent had the time to pull any schematics yet.

[Ldub]

Well, theres all kinds of stuff that can clunk. Its the how bad is it or is it getting worse that you need to keep an eye on. If you run the the VX hard, things are going to wear alot quicker. I think im going to start buy making more of the shims I mentioned before and do part buy part while testing in between. Im still waiting for the clutch pack wich is on back order from isuzu. Id recomend that the guys that own one and plan on keeping it on the road withought a long wait start collecting parts. Were lucky that the tranny parts are readily available since its a common tranny but what about diff parts. Has anyone looked into diff parts? I havent had the time to pull any schematics yet.

For the rear diff., I just ordered...

L & R bearings, a complete set of shims, & 12 ea. ring gear bolts.

All ordered from Merlin, we also talked about pinion bearings, shims, seals, & crush collar.
There was no mention of any of these items being on back order, but I won't know for sure until they do, or don't, show up next week. :_wrench:

[MoonRaker]

All the seals and bearings shouldnt be hard to find what im worried about is all the gears to include the pinion. Ask if there available if you dont mind.

[Ldub]

Sorry Moon, but my order is in & I don't have time to be your secretary...

1-800-727-8066 St. Charles Isuzu - ask for Merlin!:smilewink

[WILLY]

FRIKKIN FUNNY STUFF LMFAO :laughing:

[WormGod]

A few weeks ago when I found myself dropping the Power switch off (ya ya, so I drive more light hearted now), my clunk has REALLY decreased. By easing the shifting ranges to a more nominal setting, up and down shifting is nearly clunk-free now. Ya, I still get one occosionally, but for what it's worth, if you don't like the clunk and don't drive spirited (Power ON is hell on heavy wheels with a S/C to get the best out of it), Power OFF may very well help.

[MoonRaker]

yeh and you deffinatly notice increased milage.:)

[WormGod]

yeh and you deffinatly notice increased milage.:)

You aint kiddin'. Looks like I might actually get about 300 miles out of this tank of gas. Thats a far cry from the usual 220-240 I get normally, heh.

Had it out all weekend and not a single clunk. I made it a rule that I would NOT use the Power button at all, and I tell ya.... I REALLY missed it on the highway. Merging on and passing was painful. All I can say is, S/C + Power ON = MUST for full potential. Without Power ON, the weight of that little bastard really reared it's ugly head on that V6 and the S/C felt useless. Note to self....

[WormGod]

Nothing to really add that is constructive here. If anything, even more confusing....

So last weekend I replaced my EGR, FPR, MAF, and drop in filter. Still didnt fix my oscillating idling and continued to get related CELs. Well today I am out and about and pop the hood for a tech buddy to take a look. We find that the TPR seems to have a short somewhere in the line, as squeezing on it caused the idle to change and set off the TPR on the ScanGauge. I figure I will rewire that as soon as I get a chance and look for some bad wiring.

Well, no sooner do I leave and WOW.... my clunk is, out of nowhere, PAINFUL. Every gear, up or down, shifts with the force of Zeus and clunks loud enough to hear for blocks. In and out of Power, it didn't matter. Now, there no way that squeezing on the TPR harness caused this, heh. WTF! Seriously, it is bad enough feeling and sounding that once I got her home, she went into the garage and stayed. She is down for the count until this is solved. All fluids were checked and serviced just last year, 3k miles ago so I am REALLY baffled, and concerned.

This just might be the straw that breaks the camel's back. I have run out of patience with this thing. Under 50k miles and nothing but issues and $$$ this past year. :(

[don moore]

grrrrr. dont sound good

[etlsport]

Nothing to really add that is constructive here. If anything, even more confusing....

So last weekend I replaced my EGR, FPR, MAF, and drop in filter. Still didnt fix my oscillating idling and continued to get related CELs. Well today I am out and about and pop the hood for a tech buddy to take a look. We find that the TPR seems to have a short somewhere in the line, as squeezing on it caused the idle to change and set off the TPR on the ScanGauge. I figure I will rewire that as soon as I get a chance and look for some bad wiring.

Well, no sooner do I leave and WOW.... my clunk is, out of nowhere, PAINFUL. Every gear, up or down, shifts with the force of Zeus and clunks loud enough to hear for blocks. In and out of Power, it didn't matter. Now, there no way that squeezing on the TPR harness caused this, heh. WTF! Seriously, it is bad enough feeling and sounding that once I got her home, she went into the garage and stayed. She is down for the count until this is solved. All fluids were checked and serviced just last year, 3k miles ago so I am REALLY baffled, and concerned.

This just might be the straw that breaks the camel's back. I have run out of patience with this thing. Under 50k miles and nothing but issues and $$$ this past year. :(

mode selector switch for the trans?

[WormGod]

mode selector switch for the trans?

Ya, I am hoping that is all it is. I didn't even want to look at her yesterday, so I left her in the garage and used my WRX. Last night though, I did muster up some courage to give her attention. I at least got back to work on rewiring all the extensions needed for a S/C (since it now looks like field mice had a field day in my engine bay).


Not a transmission guy, so I am gonna have to do some soul searching on the forums about this !@#$. Seriously, hoping it's something quick and easy because my patience has worn thin enough. :(

[SilverBullet75]

I second that...
I've replaced 3 of them now (different VXs). Fixed every one. Same symptoms too.

[WormGod]

I still have yet to get around to this issue, but sitting here at work I thought I would dig around the web a bit about it.

I see folks have replaced the mode switches, but how about cleaning them? Never actually tore one down so I looked into it. Came up with this....

http://isuzufaq.ibctech.ca/range.pdf

Curious as to whether it was similar, considering it is an ISUZU module, but from a '98 Rodeo. Shouldn't be much different if anything, I wouldn't imagine.

Thought I might give it a tear down and see. Could save me the $150 or so. We'll see.

Anyone know the part# for the mode switch? I don't have any of my software or docs here at work and don't exactly wanna call Merlin from work JUST to get the part#, heh.

[SilverBullet75]

Woah... VERY interesting.
The thing I noted on all the ones I replaced was that the center white plastic "wheel" (for lack of better term) gets very loose... too much play. My first thought was that over time it melted partially from the exhaust heat nearby. Even considered adding header-wrap to the pipe. Didn't even think of reconditioning the unit.