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True trac / driveline noise...

Joe473

Sr. Member
Joined
Jul 16, 2012
Messages
950
So has anyone experienced a "hurt" true trac? I'm getting a popping and binding on slow take off. It's not the bronco clunk coming from the driveshaft splines. It's more severe and feels like. Ujoint or output pinion shaft bearing binding. Shaft and bearing feel fine. Splines go in and out smooth. Tom woods driveshaft with boot less 3yrs old now.

I may have launched it "kinda" hard with some very violent wheel hop that lasted less than 2 seconds. Ive never dumped the clutch at anything above 1600 rpm before.. this was a little above 2000 rpms which is getting close to peak TQ of my combo. Wheel hop/shake lasted just long enough for me to feel it and react, but violent enough to rip all three hangers off the exhaust system...don't ask.. I had had a long day, some asshat cut me off and I reacted poorly

I checked motor mounts, trans mounts, spring bushings, and radius arm bushing good and hardware tight. Also have my new 2.5" spring back together with all 12 leaves. Rear end no longer squatting from weight of tire carrier. Pinion angle is good. Facing about 2 degrees down from DS angle. Yes I need to control axle wrap before I break more but I don't think that is causing my current popping binding noise under very light takeoff.



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66 bronco bl

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Jul 29, 2009
Messages
59
sounds like mine years ago broke trac lock now running a billit one hats known to break
 
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Joe473

Sr. Member
Joined
Jul 16, 2012
Messages
950
sounds like mine years ago broke trac lock now running a billit one hats known to break
True trac is very different from a trac lock. No hats to break. They are supposed to be very strong... or so I thought

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DirtDonk

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They are very strong. But nothing is unbreakable almost!
But because of that, I would suspect the driveshaft or the transfer case before the limited slip.

Have you actually gotten under there and checked things yet? Pinion yokes loose maybe? Buggered driveshaft? I mean, right along with the differential the shaft is taking a big brunt of the load.
What is your gearing and tire size by the way?

Good luck. Here's to hoping it's more to do with an easy (and cheap!) part to replace rather than a diff.

Paul
 

DirtDonk

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I see the tire size is very modest. But still interested in knowing what size.

Thanks

Paul
 
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Joe473

Sr. Member
Joined
Jul 16, 2012
Messages
950
They are very strong. But nothing is unbreakable almost!
But because of that, I would suspect the driveshaft or the transfer case before the limited slip.

Have you actually gotten under there and checked things yet? Pinion yokes loose maybe? Buggered driveshaft? I mean, right along with the differential the shaft is taking a big brunt of the load.
What is your gearing and tire size by the way?

Good luck. Here's to hoping it's more to do with an easy (and cheap!) part to replace rather than a diff.

Paul
I did do a quick check of the driveshaft. It's all tight and don't see anything obvious. Drove for an hour and checked all hubs for excessive heat. Even the pinion and rear output of the d20. The rear output was hot but not severe. When I did the rear and the tcase I bought new yokes and they feel good. No slop in splines. I also did a crush sleeve eliminator in the rear.

I'm going to pull the driveshaft, the carrier and rear output to inspect and check oil for debris. :(

Tire size is only 30x9.50. With 4.11 gears. I run only 26 psi. That and the weight of the custom tire carrier keep the rear well planted on hard acceleration. Engine is a mild 9.6:1 347 with gt40 heads and 35-349 cam.

The plan is to go to a 255 75 17 or 265 70 17 in the future. Waiting for rear springs to fully settle and will prob do a set of your 1.5" front springs, 4 deg bushing and figure out a wrap solution over the winter.

M5R2 trans with 2 into 1 exhaust makes yours and duff's wrap solution incompatible.



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DirtDonk

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...M5R2 trans with 2 into 1 exhaust makes yours and duff's wrap solution incompatible.

Not completely incompatible. Just not with the existing setup would be my guess.
Lots of people running the Wrap Trap (and probably the Duff stuff too) with both dual and single exhaust. As well as with modern transmissions.
You just have to get creative with the exhaust.

Or is that M5 trans a really big sucker? Driveline shorter and the trans is in the way of the Wrap Trap cross-member?
If you need an anti-wrap device of some kind, I would definitely try to make it work. Even if it meant renewing an otherwise new and functioning exhaust system.

In fact, unless the WT was part of their original build, I'd say a pretty decent percentage of users need to modify their exhaust in some way or another.
Not so much with stock exhaust, and not if the aftermarket stuff was done in certain ways, but with the haphazard ways that exhaust can be run on an EB, a lot of installers have to modify the exhaust for the Wrap Trap.

Usually just a tweak here or there, but sometimes re-doing the whole rear exit area.

Good luck.

Paul
 

bronconut73

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Aug 7, 2012
Messages
9,916
Wrap Trap was no where near my Duff dual exhaust.

It is way up high.
In line with (ie above) drive shaft,

Hard for it to be in the way of exhaust.

Post some photos of your set up.
 
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Joe473

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Jul 16, 2012
Messages
950
Wrap Trap was no where near my Duff dual exhaust.

It is way up high.
In line with (ie above) drive shaft,

Hard for it to be in the way of exhaust.

Post some photos of your set up.
It's more the length of the trans. Longer than a 3spd toploader. Np AX etc. End of trans is right by ebrake equalizer bar attachment. Also running BC 2 into one exhaust which has muffler blocking frame rail right where wrap crossmember would go.

I could get to top of frame for wildhorses set up but would need to shorten set up a few inches.

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Joe473

Sr. Member
Joined
Jul 16, 2012
Messages
950
Here is what I found so far.

1 bad axle bearing. Not my noise but not helping either. Just over 1 yr old sealed bearing sounds and feels like crap. What's best bearing out there? This says China right on it and came with 31 spline axles... timken. Skf, federal, national??

Carrier, gears, pinion yoke all fine but mark's on yoke fron where driveshaft yoke contacted pinion yoke on hard accel.

2yr old Ujoint is bad but not bad enough for noise I was getting. Tom wood driveshaft that I thought was sealed I noticed has spliced shaft coming into driveshaft yoke. Wondering if debris and water washed away or contaminated grease. Going to bring driveshaft in and have shop spin it and do all joints. Offending u joint.

Spicer joints? Non greaseable?

Tcase output feels good. I'll pull the output shaft and open up case to inspect while getting bearings. And rear put back together.
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Rustytruck

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Feb 24, 2002
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No grease in the ujoint? Are these ujoints without grease fittings? How is the centering ball in the cv joint on the driveshaft. How many times did you retorque the axle ubolts since you replaced the springs.
 
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Joe473

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Jul 16, 2012
Messages
950
No grease in the ujoint? Are these ujoints without grease fittings? How is the centering ball in the cv joint on the driveshaft. How many times did you retorque the axle ubolts since you replaced the springs.
There was grease in the ujoint. I wiped it off to inspect and found a pretty beat up surface. Driveshaft is getting new spicer u joints with no grease fittings. Also plug was gone on bottom of shaft into yoke letting debris in. I think this may be my noise. Spline grease was contaminated.

Also year old axle shafts have bad bearing on driver side so ordered timken and new seals. Hope they last this time!!.

Checked t case and all looks good there and pulled my 9" third member and all looks good there as well with gears, tru trac and pinion bearing/yoke.

On the u bolts I did check them before everything else. Got a full turn on each but no difference.

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surfer-b

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What's best bearing out there?

Not saying these are the best out there but I have had really good luck with them, plus you can run the factory axle seal along with these and have double seals, that's what I do. these bearings are sealed and have an O-ring seal on them, just make sure you get the correct size.
https://www.summitracing.com/parts/...xMlvQ_qAlrNLXBP6zIhTT8HNfoMfayTgaAo7ZEALw_wcB

Also year old axle shafts have bad bearing on driver side so ordered timken and new seals

I hope you get a set of US made Timkens, I see a lot of the Timken stuff made over seas now
 

surfer-b

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If you use the Moser bearings make sure the axle housing is free from nics and burrs, if not it may cut the o-ring seal when installing
 
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Joe473

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Jul 16, 2012
Messages
950
If you use the Moser bearings make sure the axle housing is free from nics and burrs, if not it may cut the o-ring seal when installing
Thanks for that link on the Mosers. I have the timken coming. If they end up bad again next year I have another source. Waiting to hear on shop checking out driveshaft. A d the. Putting this all back together Saturday. I hope.

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DirtDonk

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Forgot to ask just in what way the current bearings went bad?
And what brand were they? Keep your receipts with the Timkens just in case. In fact, if you have the receipt for your old ones maybe they're still under some kind of warranty.
Most companies will realize that in a Bronco you are not going to have very many miles on a 2-year old bearing. Although they could still throw the old "you used them off road" roadblock at you.
Or the big tires, or whatever.

But they should still have lasted longer than this unless they're the small bearings and you really load them down.

So what exactly let you know they were bad?

Thanks

Paul
 
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Joe473

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Jul 16, 2012
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950
Forgot to ask just in what way the current bearings went bad?
And what brand were they? Keep your receipts with the Timkens just in case. In fact, if you have the receipt for your old ones maybe they're still under some kind of warranty.
Most companies will realize that in a Bronco you are not going to have very many miles on a 2-year old bearing. Although they could still throw the old "you used them off road" roadblock at you.
Or the big tires, or whatever.

But they should still have lasted longer than this unless they're the small bearings and you really load them down.

So what exactly let you know they were bad?

Thanks

Paul
So the bearings sounded worse than the 45 yr old bearings I replaced last year. Believe it or not I heard the growl over the open top and exhaust around 40 mph. I didn't think this was my binding and grunting on takeoff but if I was pulling the third member to check the true trac and gears I was doing them. When I pulled the axle and spun the driver side it sounded like a dry bearing and had a "digital" feel or lumpy feel whe. Rotating by hand. My 45 yr old bearings sitting on original axles sound and feel better!!

These came pre-installed on 31 spline small bearing axles from another vendor. The only Mark's on them were CHINA and a part number. Other than cheap bearings the only other thing I can think of is when they installed them they put pressure on the outer race causing the seal and bearing to fail.

New Timkens installed tonight and third member back in. Calling and picking up driveshaft tomorrow. The DS shop has a serious opinion. On my 2 yr old driveshaft they want to talk about.

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DirtDonk

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Thanks for the details.
Good luck with all the new stuff.

Paul
 
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Joe473

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Jul 16, 2012
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950
Thanks for the details.
Good luck with all the new stuff.

Paul
Thanks, noise is gone! Had a Ford mechanic tell me to get rid of blue paraffin on the splines and use Ford teflon grease. Cleaning and greasing splines and changing the lower ujoint got rid of it.

The driveshaft shop was not a fan of my drive shaft. They said my shaft felt nice and smooth but had a slight bend to it and wouldn't replace ujoint or attempt to balance cause they didn't think it would balance and u joints felt fine. This is a reputable shop. I spun it at about 500 rpm installed and don't see any noticeable bend. There has been some vibration but that may also be my recent tire rotation. Need to rebalance before jumping to conclusions on the shaft.

Also not sure if I mentioned but it is a long travel shaft and the splines portion goes into the rear yoke. I thought it was sealed but there was no cover and a good amount of contaminated grease when I took it apart. It's weird they go through the trouble of a dust boot but no end cap on the bottom!! Amy one else out there have a DS with a boot over the splines? Is there an end cap on the lower shaft .

We will see how it goes and if the noise comes back. Anyone have a good reputable driveshaft shop in NJ?

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DirtDonk

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The end caps are just stamped steel discs lightly pressed/swedged into the end of the tube. Even just one instance of over-filling the shaft with grease will literally hydraulic the end cap right out the bottom on the first big bump.

Could have come with the cap originally then, and been launched out the back at some point.

Paul
 
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