Plasticman

As some are aware, I purchased new Traction Masters for my 62, after having wheel hop issues.

Here is a thread I started a month or so ago.

http://forums.corvetteforum.com/show...ight=wheel+hop

Well, with more than a little help from DZAUTO (Thanks Tom!), I made a set of bolt on brackets for the front mounts.

I will post some pics later. But now for the news of how they work.

First, I left the OEM radius rods on, since they do serve a good purpose, and with the front Traction Master mount being the pivoting type (pivots on the leaf spring front bolt), there is no issue of binding between the raduis rod, the spring, and the lower traction bar (like what I feared if I used the supplied weld on frame mounts). I did need to make the new mounts a little longer than Toms, since Traction Master has made my bars 3/8" shorter than Tom's older bars. Since the mounts pivot, at full load they must pivot forward, and then stop on the front spring mount vertical plate. I made each plate so that I had the same air gap between the plate and vertical plate (in the static position with the tires on the ground).

That said, the ride is the same as before without the traction bars. No diff. at all.

However, it appears that my posi unit has given up. The one and only time I tried getting on it from a dead stop, I fried the right rear tire and left a long single black stripe. This is something completely new, since it always has left 2 black stripes. I cannot see anything in the traction bar setup that could cause this, so I must assume it is the posi unit, and will pull it next week.

I also tried out the bars in the 1st to 2nd shift (where I was also getting wheel hop). This time, it did hop a small amount, but then the Vette jerked to the left severely enough for me to have to lift (could not steer out of it). I cannot explain this, and has me concerned.

I checked the traction bar front mount left and right "contact points" (where they contact the front spring mount vertical), and see paint "removed" from both side, so I don't see anything "unequal" happening there.

Comments?

Plasticman

DZAUTO

In college physics, I learned that when you use your RIGHT hand, and wrap your fingers around a shaft, wheel, etc., with the fingers pointing in the direction of rotation, and stick your thumb straight out, the thumb is pointing in the direction of torque.

Also, if only one wheel is turning with the new bars, then yes, you probably need new posi clutches. They are (or just recently were still) available from DANA. The DANA part number is 22233X. Many drivetrain suppliers carry the DANA line and they should be able to order a clutch pack for you (order 2). The clutch pack consists of 10 plates/discs. Assuming your posi unit is in fact a 60-62 (60-64 for pass cars) unit, it will have 10 plates/discs. BUT YOU ARE ONLY GOING TO USE 8 FROM THE NEW PACK!!!!!!!!!!!!!!!!!! The original clutches have 8 that are the same thickness and 2 thin ones (one on each side). RE-USE THE THIN ONES, IF THEY SHOW WEAR, SIMPLY FLIP THEM OVER!!! Two of the new plates will be convex (its called a Bellville plate). It goes in the center of the clutch pack on each side. Thus, the arangement, from the outside to the center is: Thin plate-splined disc-Bellville plate-splined disc-thick plate. DO NOT THROW AWAY THE OLD CLUTCH PLATES!!!!!!!!!! Keep them until you die or sell the car! (or send them to me)

AZDoug

To eliminate a possibilty, double check your axle U bolt tightness.

Doug

MikeM

The way I read (and re-read) the front bar mounting, it seems like your front bracket is not fixed but rather is laid back normally but swings forward against a stop under torque? Never seen one like that if it is. Got a picture?

Your LEFT wheel running wild is unusual to say the least, even if your posi clutches are gone. Did you break an axle?

DZAUTO

This is my 56 with ORIGINAL Traction Master bars for the early Vettes, Showing the forward end.









I've added 59-62 style traction bars and the 60-62 style rear sway bar too my 56. This is how Traction Masters look with the 60-62 rear sway bar.

Plasticman

Case of CRS. Yes, it was indeed the right tire going up in smoke! I changed it in my original post too.

Will show pics later on tonight.

Thanks,
John

Plasticman

Tom,

Thanks again for all the posi info. Just to prove the point, I am going to remove the bars tomorrow and try it without them (easy enough, and I don't want to tear something apart when I don't have to). But as of now, I too am convinced it is the posi unit.

John

Plasticman

Here are the pictures.

First is the front mount with the bar attached:


2nd is with the bar removed and the pivoting plate rotated towards the rear (note space between the vertical on the left, and the plate front edge, and also the paint removed from the front edge of the plate where it contacts the vertical under full torque - as see in the last picture).



I just did a torque test to determine if the posi clutches are "gone". Only takes 47 ft-lbs. to break the clutch pack loose (rotating one wheel with torque wrench while holding opposite wheel steady). I think that is very "loose"! So I guess I don't need to try it out again tomorrow (without the bars). That case is closed! Still don't know why I got the jerk to the left when I shifted from 1st to 2nd (and yes, it was to the left ).

I also noticed a lot of rotational looseness/clink between the axles (both sides) and the clutch packs. Hope the splines on the axles are OK.

Also checked the the axle U-Bolts (thanks Doug), and they were all in the 55 to 60 ft.-lbs. range (retightened them back to 60). Thanks for reminding me.

Plasticman

AZDoug

If you get a clinking noise inside the diff turning a wheel back and forth, you may have split the posi case.

47 ft-lb torque isn't what i would call weak, they are designed to allow rotation of one wheel, while the other is stopped, assuming the differential rotation is applied at the wheel.

Doug

DZAUTO

The OLD, or original, style clutch packs (22219X) from DANA contained all the CORRECT plates (I don't have a clue why they changed with the 22233X pack), which included the correct thin plates (2), 2 Bellville plates, AND, 2 Bellville splined discs. If you wanted the "factory" style preload on the clutch pack, then only the Bellville plates was used and one of the FLAT splined discs was re-used. But if a higher preload was desired, then BOTH the Bellville plate and splined Bellville disc were used which increased the preload on the posi clutches. I always built posi units with both Bellville plates/discs. Once upon a time, you could buy individual plates/discs, but not any more. You can only get the 22233X clutch pack. Several months ago, I noticed someone was advertising clutch packs which included the correct thin plates------------------------FOR A CONSIDERABLY HIGHER PRICE! But, you get the required thin plates.
Here is what I've been doing. I NEVER throw away anything (I've learned the hard way!!!!!) I have always saved the old, worn clutch plates when building posi units. Several years ago, I took a stack of old, worn, THICK, flat plates, along with one thin plate, to a machine shop and had him surface the worn thick plates down the the thickness (~.062) of the thin plate. Now I have an inventory of thin plates to add to customers' posi units during a rebuild. I'm stacking up the NEW thick plates that I don't use from the 22233X packs to again someday be surfaced down into thin plates.
When I had these old thick plates surfaced down the the thickness of thin plates, he charged me about $5ea. So that's about $10+ additional for posi parts. If you have a 57-62 Vette (or 55-64 pass car) with an original style posi in it, I would strongly encourage you to locate a store that carries DANA parts and order a couple of clutch packs (DANA part number 22233X). Just like everything else, they will someday be discontinued.

Plasticman

Doug,

I doubt that it is a cracked posi, but I will find out once I open it all up. It appears to be just slop between the axle splines and the clutches/differential gears (or maybe the gears themselves). It makes no noise at all while driving, and works just fine (until you "need" the posi). I do have a spare 4.11 with posi center section complete that I can use if needed, that worked just fine before switching to the 3.55 center section.

As for the 47 ft. lbs. breakaway torque of the posi clutches, the first test was to turn the wheel/tire by hand (while the other wheel was stationary). I have never been able to that on any posi rear I have owned, but could with this unit now. The 2nd test was to determine exactly how much torque was required to have the clutches slip (hence the reading of 47 ft. lbs.).

Thanks,
Plasticman

Plasticman

Tom,

Will start the search for the Dana clutches today. I tried online, and it went nowhere. Zip Corvette does sell clutch packs, but who knows from where.

http://www.zip-products.com/Zip/prod...96552C9E2468A5

Just trying to figure out what all I need to replace the clutches, and hoping I don't find other damage as well.

Thanks,
Plasticman

DZAUTO

UNLIKE a posi such as the Eaton, The DANA posi MUST be removed from the rearend case to service it (replace clutches, spiders, etc).
The DANA posi unit is bolted together in 2 halves. The 57-59 units have RIGHT HAND threaded bolts. The 60-62 (64 on pass cars) units have LEFT HAND thread bolts----------------BE AWARE OF THIS SO THAT YOU DON'T TWIST OFF A BOLT TRYING TO REMOVE IT!!!!!!!!!!!!!!!!
Consequently, the posi, with ring gear attached, has to be pulled out of the case. When you do this, just be sure to keep the L&R bearing races with the same side. No big deal. The bearings will NOT BE damaged! BEFORE removing the bearing caps, use a hammer and center punch and mark the caps and case (I put one punch mark on one side and 2 on the other side) so that the caps go back as they came off. Also, the 2 halves of the posi case are machined as a unit. So, make a punch mark on each half of the case so that you put it back together as it came apart. I can't post pictures from work (gov't firewall) to show you.
In order to put it back together with the same backlash/bearing preload, also mark the adjusting nuts (keep them on the same sides) so that all goes back together as it came apart. It will be obvious when you get it pulled out.
There is no need whatsoever to disturb the pinion, UNLESS, you need to replace the pinion seal. If it's not leaking, don't fix it.

DZAUTO

Plasticman,
This is your lucky day!
The place in OKC, Drivetrain Specialists, http://localsearch.live.com/localsea...t=yp&FORM=LLSV
has ONE 22233X in stock, plus, DANA has 4 in the warehouse. Go to this site, call the 800 number and talk to Danny. He will ship it to you if you wish. You'll like the price!

Plasticman

Tom,

Thanks for all the help & info! Clutch pack has been ordered.

John

JohnZ

The original Traction-Masters that were on my '57 when I rescued it (and left in place when I subsequently restored it) had the forward mounting plate welded solid to the outboard face of the spring hanger bracket (not pivoting as yours appear to do). I never had any kind of noises, chatter, or axle hop of any sort, as there was no looseness in the system; perhaps the pivoting of your bracket is allowing some action/reaction slop at the mounting point, which could cause some wheel hop.

Plasticman

John,

I agree it is possible (and probable), but until the posi is repaired I will leave it and try fine tuning unless it proves fruitless (and go to the welded setup). The welded setup provided by Traction Masters welded to the bottom of the frame. Since that area is not flat (would of either needed to be ground down, or up to 1/4" thick shims added in places), I was not in favor of that. With the existing pivoting plates, if I choose to weld, I can just weld these pivot plates directly to the spring hangers (like yours were). Overall a much "cleaner" system, and easily removed completely by using new spring hangers if ever required.

One way for me to test that theory (without welding) is to insert metal shims between the pivoting plate and the vertical plate that it "stops" on (to take out the slack). I would also tighten up the spring hanger bolt, to reduce the chance of any looseness.

My reasoning for using the pivoting system (like Tom's) was it allowed the retention of the upper radius rods. With a "fixed" lower bar, the upper bar would need to be removed (to prevent binding from having a "6 link system" with the leaf spring in the center changing lengths as it flexes).

Note also that I have retained the anti-sway bar, and that item will also induce wheel hop (side to side). So I may end up removing it, although I don't want to (to maintain as much handling as possible). This is a long term project (has been going on since I first "discovered" the wheel hop in 2000), so I am taking it very, very slowly (one benefit of being retired).

Thanks for your thoughts.
John (the Plasticman)

OC-1

John, the bars that were on my 57 look quite similar to yours except they are completely bolt on.

Where yours are welded to the spring bracket mine bolt on. The forward attachment looks the same. The plate that bolts to the spring perch has a corner cut formed so 3 of the 4 U bolts actually are used to attach it.

The 3 cornered plate has the raised letters/#s CP 53-54.

Is there any identifying marks on your set up?

Thanks,
Joe

Plasticman

Joe,

JohnZ no longer has his 57.

John (Plasticman)

Matt Gruber

the 47 is fine.
my 72 has only 25 and burns the 2556015 evenly.