Rear thunk. Slip yoke or axle wrap?

06 Tacoma prerunner. 48500 miles. When i come to a stop at a stopsign or traffic light. I am experiencing a loud clunk from the rear end. This happens when I release the brakes.

I'm just wondering which could cause this. Not real sure as both symptoms sound similar.

 

check u-joints???

 

No I haven't. But would that cause it? It's just when I am at a stop. When I release the brake it's when I feel the brakes releasing. The moment I feel the brakes stop grabbing, the clunk ensues.

 

it could because when you break you are [so called] reversing the pressure on the driveshaft

crawl under the truck with it on level ground and in park or gear and try to twist the drvshaft back & forth by hand to see if you can get it to make the noise your hearing

 

It's the slip yoke. You need your driveshaft replaced. Ask the dealer. Took me 6 mo to finally get it done

 

X2

Or specifically....look for driveline slop. If you're in park / gear and you rotate the driveshaft by hand, you shouldn't have much movement at all.

I know my 96 had a good amount of play in it and lurched like you described.

 

If the dealer performs my suspension tsb this weekend as planned. Ill see how it
Is afterwards. If not. I'll complain till they fix the clunking, which of course they will say is normal. Ill mention it to them when I take it in.

 

I had it too... it's a combination of axle wrap and the slip yoke. The axle "wraps" a little and the slip yoke extends then binds when it tries to retract. It's very noticeable with automatic because the engine is still torquing the axle to wrap it as you're braking to a stop and the sticky slip yoke holds it wrapped. When you release the brakes everything unwinds with a noticeable THUMP.

Lubing the slip helps but you have to do it frequently... at least with every u-joint lube, and it's difficult since it doesn't have a zerk.

I attacked the axle wrap by clamping the leaf pack just in front of the axle. Together with the spring TSB, it has done a great job of reducing the thunk to almost nothing by not letting the axle wind up. But it also made the rear suspension a good deal firmer.

They will say it's normal 'cause apparently it is! Keep after 'em but I don't think you'll get them to make any mods for you, and you need at least one of two: stiffening the rear suspension to keep the axle from wrapping (which is what the clamp does) or a zerk in the slip joint to ease lubing.

 

How do I clamp the leaves? And use what?

 

I started with over-load springs mounted upside down like a 'slap bar'. It worked great but I was worried about them slapping on the springs as I went over bumps and reduced it just to just the clamps which did about 90% as well.

You can get just the U-clamps at Pep-Boy in their 'speed' section where there are a number of leaf spring mods to alleviate axle wrap and axle hop which was common with 60's muscle cars.

I put the clamps about 4" in front of the rear axle. There are several threads on it in TW, search and you'll probably find one with pictures and everything.

Oh yeah: getting the TSB suspension, since it's stiffer, helped but did not make it go away to my satisfaction. The clamp did though.

 

Well here's an update.

Took to dealer for tsb leafs. They said they have to have a tech come out Tuesday to approve. Grumble.... Sat for an hour this morning for nothing. Anyway. Was gonna have brakes checked for that thunk sound. They were gonna charge me 50 for diagnostic. Grumble again. Maybe they will approve it. Hoping they do. Gotta love new leafs and shocks for free.

 

Make it a slam dunk for the tech: load it down so it hits bump stops over traffic humps. He'll have to admit it's bad. I used sand bags as they have a pretty standard weight so they'd know it's not overloaded.

I don't know I've ever had to pay a diagnostic fee on a warranty complaint... doesn't sound right to me.

 

They say it was because the brakes are a wear and tear part. Whatever. I'll have my trusty STS auto center look it at next time it's in for oil. I trust them. And they have never steered me wrong.

Anyway. Apparently if the tech doesn't approve they will try and good will it for me. I'm not holding my breath. This truck has more wrong with it than I could have ever imagined.

 

Oh... I missed that you're pushing 49K miles! Warranty for the TSB springs is really not too likely, but will be nice if they did good-will it for you.

If you can't get the TSB then I'd suggest what Bandit did: put an AAL in. They work better than TSB suspension anyway and that should take care of axle wrap and the thunk at the same time.

Axle-wrap is really common with RWD leaf spring suspension cars and trucks, back in the day, before front wheel drive, rear coil spring suspensions were the thing to have for a comfortable ride. Then consider that this truck (stock) is softly sprung just makes it worse, and with automatic and a slip yoke thunking is almost inevitable.

 

Well. Money is kinda tight right now. So the aal would have to wait. Will this thunking cause damage? Or can it be left alone? ( it isn't all the time, just randomly). Btw. Doubt it's the calipers or brakes at all, since there's no real pattern that causes the thunk.

 

If you want it fixed get a new driveshaft. You problem is the same as mine was. Period. I don't know how else to get it through your head

 

So my driveshaft is bad?

So did I really just spend my entire budget on a truck that is going to fail?

I can't afford a new driveshaft!

 

Warranty should cover it. It's the slip yoke.

Maybe it can be rebuilt??? Or look at toms wood 1 piece if not under warrenty

 

Well the dealer says the thump is related to the brakes and won't cover the diagnostic charge. So. I guess I'm stuck doing the following. Going o the dealer Tuesday to see if I'm approved for that leaf spring tsb. If so, I'll let them do that. If that solves the thunking(axle wrap) I'll let it go. If it doesn't, I'll stomp and complain till they do it. If they deny my leaf request. I'll still stomp and whine till they fix it.

 

I'll see if I can find my service receipt