My turn for some differential work

Todd & Kris · #1 (**permalink**) 01-13-2002, 10:17 PM

A while back I posted a question somewhere on this site regarding the bouncing and chattering I was feeling from the front end wildst tuning sharply at slow speeds. Well I figured it out.

It's not the front end, but rather it's the rear end. Ever since installing those sticky Goodyear Racing Tires, and the fact that I have a full locker. The tires don't slip/give like the other tires when I'm turning sharply at slow speeds, and so when I'm turning the rear tires stick, skip and jump. Thus chattering the whole car.

The full locker is just too much, and I know I have a 28-spline 9". After hearing the recent stories and knowing the horsepower I have, I think it best to upgrade to a 31 spline with limited slip set-up. I'll pull the differential next weekend, and take it in to Dan for a diagnostic.

Is everything I'm saying and doing making sense?

Todd

Gordon Claunch · #2 (**permalink**) 01-13-2002, 10:37 PM

Todd, I don't know what your going to use , but I just put a powertrax no-slip in my car, it gives you the full locker, but will disengage when turning, really a sweet unit, gives you the best of both worlds, pretty easy install, about 2 hours for me, I have never had the back off a differential before

so it may take someone more experienced less time, from what I've read these are top of the line units!!

ERA535 · #3 (**permalink**) 01-13-2002, 10:51 PM

Good move on the switch to a limited slip....full lockers are great to talk about but the reality is not so good. On the street that is.

Did you ever notice that your car would sometimes push like a pig if you got on it coming out of a turn? That is one of the other drawbacks to a locker.

Bish Wheeler · #4 (**permalink**) 01-13-2002, 11:01 PM

Todd,

Having just been throught this drill, I now know a little more. I installed the "Truetrac" rear end and 31 spline axles. The nice thing about it is there are no clutches in it. Very simple and fool proof, plus no "chuddering" in turns. Check it out with NWD and Zderf.

Bish

Zderf · #5 (**permalink**) 01-18-2002, 01:50 PM

Todd, for your street use you'll love it!! And face it, you on the street way more that SIR!!.

Tell Dan I said Hi!!

Zderf

Todd & Kris · #6 (**permalink**) 01-18-2002, 10:40 PM

ZDerf;

Dan sends his regards.

Now I'm thinking about just driving the car in and having them do all the work. No time to remove the differential and take it down. Looks like it's going to run about $1800 with tax, turn-key.

True-trac, 31-spline, 3.25 gears, and all the rest. They need the car 10-days. Should I do it? Ouch!!

Todd

Bish Wheeler · #7 (**permalink**) 01-18-2002, 11:11 PM

Todd,

With the power you are running those 28 spline axles are the weak point and if they "go" it's gonna tear things up. Then you can add a towing charge on top of everything else.

If you can afford the swap then for sure you should do it. The street performance will sure be more enjoyabe. I didn't have a locker in my car before, but the posi was pretty worn and the left axle had a twist in the spline. I switched from 3.23 gears to 3.70. It made all the difference and only upped my 70 mph rpm by 350. 'Course you're running a lot more power than me, so your gearing is probably just fine at 3.20. My $.02 worth.

Bish

Double Venom · #8 (**permalink**) 01-19-2002, 05:53 AM

Todd,
FYI:

The original DV went through so many rearends I lost count. That 1.51 second 60' time is a reall killer on rear ends. We went through semi-lockers, Auburns (that one made about 4 hard turns on a roadcourse and blew the clutches), and seriously modified 9" Fords. Finally, at the Viper Nationals we split the 9" housing in half on a launch.

All for naught. True-Trak/Lok, wanted me to try one of their rear ends and guaranteed it! Even to the point if we didn't like it they would refund 100%.

Bottom line, this unit has been marvelous! You will feel some very minor "clicking" going around corners at low speeds and you may even hear it. Not to worry, it just tells you the unit is working. Not that those two big wide black marks behind you wheels isn't evidence enough!

Just my 2-cents.
DV

PS I think the unit itself is around $750.00 ?? $1050.00 seems a little high for installation...or are you including the 31 spline axles?

Back in Black · #9 (**permalink**) 01-19-2002, 09:37 AM

Vern Redel of West Coast cobra, (my builder) recommended, and I am going with, an all new Strange Engineering rear end...modular posi differential, 31 spline, new axles...total cost with bearings and everything is about $2150....but you probably just want the differential, which is $1650

I am going with 3.00 gears, as I have a ROD (Richmond Over Drive) 6 speed manual transmission, low first gear will make it all work out. The entire affair (rear end) is going to be painted in emeron or epoxy black paint.
(Space frame is in red emeron paint)

BiB

Double Venom · #10 (**permalink**) 01-19-2002, 10:58 AM

BiB,
Imron is some tremendous paint. When it first came out years ago I tested it on a 115 hp outborad propellar. Painted it orange of all things. At the end of the season, just the very, very edge had worn off.

If you can, we'd love to see some pictures.

DO NOT spray Imron at home people...this is some bad stuff!
Forced air supplied mask is mandatory!

Isocyanates never leave the body

DV

Back in Black · #11 (**permalink**) 01-19-2002, 11:07 AM

It's a turnkey, and being built over 2,000 miles away, so I only have a few pics sent by the manufacturer, so far. I promise as many pics as he sends. All I have right now is pics of my motor as delivered.
As soon as I can calm down, after delivery, will take mucho pics and post the good ones in my profile, and other spots here.

I learned about the Emeron paint when I was an R & D tech, working on down hole high tech oil drilling electronics... it's like NASA stuff

Todd & Kris · #12 (**permalink**) 01-20-2002, 11:09 PM

DV;

The price included new gears, bearings and new hardened steel axles.

I'll make a decision here pretty soon?

Todd

Todd & Kris · #13 (**permalink**) 02-03-2002, 07:38 PM

Well, I decided to take on the task myself, with my talented brother-in-law. The axles were in great condition, so they are keepers!

The true-trac is on it's way with the taller gears.

Todd

P.S. I'm working on some pics of the process.

Todd & Kris · #14 (**permalink**) 02-03-2002, 07:39 PM

picture to come?

Todd & Kris · #15 (**permalink**) 02-03-2002, 07:40 PM

Picture 2 to come soon?

Bish Wheeler · #16 (**permalink**) 02-04-2002, 04:41 PM

Good news Todd. With the axles in good shape you save a ton of $$$. I think the Tru-trac is pretty easy to install.

Bish

Bob Parmenter · #17 (**permalink**) 02-06-2002, 10:25 AM

Hey Todd,

Do yourself a favor while you've got all the labor invested in tear down. Have the axle splines checked for cracks. These are notoriously "weak" (in relative terms). Even though they'll usually show some twist before failing, why take the chance?

Zderf · #18 (**permalink**) 02-06-2002, 11:00 AM

I can vouge for the twist......

Feast yer eyes on this (not to mention collateral damage in the 100's)..

Zderf

Bob Parmenter · #19 (**permalink**) 02-06-2002, 11:26 AM

Hey Fred,

Great pic! That should make a believer out of any doubters. You gotta have a picture for almost any occasion.

Thinking of one of your other posts poses a burning question in my warped little mind:
If women get menopause, shouldn't men then get womenopause?

Bish Wheeler · #20 (**permalink**) 02-06-2002, 11:53 AM

I looked at my earlier post and have re-thought it a little. From what I learned in my go 'round with this thing, the 28 spline axles are usually cut from standard axles and are not hardened. The 31 spline versions are oversized and hardened. They run about $250.00 each. Breaking an axle, like Zderf did, will pobably wipe out your new rear end which puts you back to square one. As Bob said, why take the chance.

Bish