Can anyone tell me why every time I let off the brake after coming to a complete stop my truck makes a bumping sound that I can fell and hear. I also see the shifter in the floor move quite a bit it time it bumps. I don't think it's the drive shaft because all the U-joints are in really good shape. I do know the shocks are bad and I plan to replace them so could it be them or could it be in the tranny or the rear end? Any insight would be greatly appreciated.

Thanks,
Rob

 

It's the infamous axle wrap, notoroius in all Tacos. Check to see if your leaf packs have de-arched. Getting new ones or re-arching them will most likely solve their problem. You may want to grease the driveshaft zerks and spline if you haven't done so already. I replaced my flattened leaf packs and greased the driveline down recently and made a world of difference, drives like a new truck now.

 

Would a AAL help at all cause my leafs are flat now too.

 

How much does it cost to re-do the leaf springs?

 

Generally the more leafs you have the less axle wrap you'll have.

 

That depends on where you get the leaf packs from. Give Alcan a call and get a quote for the best, then compare to the rest. http://www.alcanspring.com/

 

So what is the leafs doing when they cause this noise or can the term axle wrap be explained so I'll know what's going on?

 

The axle twists as you apply power to the wheels. Picture how a dragster will wheelie off the line, your axle is starting to wheelie because the connection between the axle and the frame (leaf springs) is too flexible. There is another option besides stiffer leaf springs, it's called a traction bar. It will help stop the loosey connection between your frame and axle.

 

Here's a picture of an Alcan spring pack:
http://home-and-garden.webshots.com/...42310107BxPnsh

Here's a pic of a Budbuilt traction bar slightly modified: http://rides.webshots.com/photo/5470...42310107kZrJbf

 

Here's a thread going on the 86-95 forum about what springs are best: https://www.yotatech.com/forums/f116/ome-vs-downey-vs-alcan-rear-leaf-springs-90376/

 

Now that's a set of springs and a mighty nice traction bar too!

I understand now Dale, thanks for the analogy. I see a slight sag in the rear right now but I do have a Leer camper shell on it so I guess that is some of it...maybe the new Bilstein HD's will help some with that too...They will be here soon....as for the leaf replacement, I may have to wait a little while on that.

 

Before you spend a bunch of money on suspension, grease the crap out of the slip yoke on the drive shaft. Grease it until it comes out the slip yoke and see if that helps.

 

New shocks may help a little but you really need to focus on your leaf springs.

 

Thanks for the advice guy's I'll see what I can come up with.

 

I'd be carefull about over greasing the slip yoke. I've seen the end cap of the drive shaft blow out from too much grease and it's really just a bandaid fix anyway.

Also keep in mind you get axle wrap from stopping quickly too, not just acceleration. I think this is made worse by the sagging springs loading the rear brakes too much. This is because the load sensing proportial valve (LSPV)thinks you have loaded the bed full of weight and is valving the brake pressure too much to the rear brakes. Try hard braking sometime on wet pavement and see if your rear brakes are locking up before your front brakes (only works with non-ABS trucks of course) If they do, there are ways you can fool the LSPV into valving less braking pressure to the rear brakes. Or you could just try braking sooner & softer, probably save on gas too.

 

Yeah, I mostly feel the bump right as I come to a comlete stop or either right when I let off the brack after being stopped. I never feel the bump when I have my trailor and ATV hooked up....and I never feel it when I hit the gas....Does that sound about right?

 

Yeah I think that's when most report hearing it on the Tacos. I've heard my worst clunks (93 truck) when accelerating hard in reverse and that would be wraping the same direction as stopping would.

 

After reading this thread I looked underneath my truck, my leaf springs have no bow at all. I guess its time to replace them. I am going to give that spring place a call.

Thanks for the tip.

Now making calls for quotes...

 

I just looked on my 2001 Taco and there is some adjustment for the LSPV arm at the axle. I found a good adjustment for my 93 after my 5" lift by using a thick, stiff wire to hold it stable at the proper angle. I tested it on wet pavement a few times to get the adjustment right. The higher the arm (closer to the bed) the more rear braking you'll have. When the rear sags with weak springs the arm is closer to the bed and you have more rear braking. Or you can modifiy the arm bracket too, or some just cut the arm off up at the LSVP.

 

I get the same thing also on my 2001 Taco auto. So does a guy at work that just bought a 2006 Taco DC auto. I have noticed that putting the tranny in the power shifting mode (ECT switch on) that the clunk is mostly gone.

All this discussion about the Taco clunk on this board and others and I have yet to read about anybody that took it to the next level and did an actual eyeball of the drivetrain during the clunk instant. Takes 2 people. If you don't beat me to it I am going to get my sister to drive it....fast stop it to get the clunk noise while I observe. Hopefully she does not run me over ZUK

ps--I think it might be the DS carrier bearing.