rear end gear change..how easy is it?

[Qualitywires.com]

Has anyone changed their rear end gear out by themsleves? I'm talking about the average do it yourself type guys. I got my power tools and looking to do some upgrades. I think my first major upgrade will be the gears.

I just need to decide which one is the best for me. I want one on a roll...it will be aggressive, but at the sametime, I don't want to be driving 50mph in 5th gear either (top end)...if you know what I mean.

 

[Gerald]

Adam,

There was a thread about 2-3 days ago that BEAT this topic to death! Someone might know where it is. With all the post moving around, it might have gotten moved to performance or something, but it used to be here..*(I think)


Gerald


p.s
Come down to bradenton this weekend!

 

[jimandela]

Ab,
I really want this upgrade. and even started a thread here to help find someone to do the swap. It is now going on 2 weeks and still have no one!!!
I tried Tator dodge besides a 5-6hr ride it couldn't be done in 1 day.So I tried Wellington dodge 1 hr away, they never done one but would be happy to try (no way!).
My local tech is trying to get intouch with a shop that has a
"old timer" that does only rearend gears swaps. He was out of town so waiting on a answer from that lead.
I told JonB minute i find a local shop i would get the 3.55 gears!! but finding someone is rough, so i wouldn't go it alone!
The service manual shows the swap it looks involved.

In the end, if no one can do it, I will ship it out to be done.
but that too is pain,because of about 1 week turnaround means the car sits at dealership garage(could get scratch,etc,etc.)

Good luck
JIM

 

[Qualitywires.com]

Gerald, I would love to come down and visit this weekend, but have to wait until I get time. I'm behind on work right now! Man I actually got a nice response from you this time and no heckling from ya! heh!

jimandela:

i'm not if I'm brave enough to do it myself. I got my power tools and removing the rear end for me is no problem..I'm not sure about the internals. I wouldn't think it would be a problem, but maybe time consuming at first. I don't know. I guess I will have to do research on it. If there's gauging involved, then I won't do it myself. If it's just a simple take some bolts off and get some oil on yourself..type job, I can do it...but I will have to look into it. I think I will go with the 3.55 or 3.73's...not sure yet...more like the 3.55's since it would be a good mix of driving.

 

[Paul Hawker]

From my understanding setting up the gear sets is an art into itself. Too tight = noisey...Too loose = weak. Lash can break teeth.
I watch the guys at Unitrax do mine in Calif. It took them some time to get it just right, and the results was a very quiet, and more responsive car. Been in other cars where the rear was real "whiney"
Compromise would be for you to use your handy tools to remove your rear pumpkin, box it up and send it to be rebuilt with new gears, and then put it back in yourself. Hardest part is often getting exhaust pipes off on GTS's. RT/10's not an issue.
The gear oil is critical. The wrong stuff will quickly ruin your limited slip.
Any way you go don't use 3:73's. A little too much gear. 3:45-3:55 just right.

 

[jimandela]

Ab,
My vipertech would not touch the project, and the only other vipertech in town said he did a reargear swap once and would not feel comfortable doing it again.

It sounds like it is a tough job that you need experience doing.
Don't want to screw up your car.

I trust my tech and tried to talk him into and he said "no way"!

I will go 3.55 because my car is for street only and it seems like the best gear for the street!
If you do decide to try it make sure you have the service manual.
it details how; the 2001 manual pages 3-29 thru 3-40!
good luck
JIM

 

[Chuck 98 RT/10]

Before you guys do this will you please make a dozen or more 1/4 passes and then the same number of passes after the mod and then average them out? I have yet to see any concrete info on this mod improving times.

AB, I've always been told to let a pro do the actual gear change because of the precise tolerances required.

 

[Paul Hawker]

I ran before and afters at Pomona. Best times before installing 3:54's was 12.15. After install ran multiple 11.9's. Now I know that that sounds like not such a big thing, however I was very very proud to be presented my 11 second club hat!.

Car was 96 GTS with SVSi headers, K&N's smooth tubes.
Car was much more fun to drive after the install.
Car was also much more thrilling at the track. Came storming off the corners, however extra shifting probably negated any time improvement.

Change the gear to make your Viper more exciting, and responsive, not to make it significantly faster on track.

 

[Chuck 98 RT/10]

Finally! Actual numbers, thanks Paul. Sounds like that was the only change you made and you got a solid .2 upgrade, which I would call significant.

 

[TOOOFST]

No, might not be enough so here's the answer, by question!
You could port&polish your heads for $100 worth of craftsman tools,would ya do it?

 

[VIPR GTS]

When I ordered mine I was advised by my tech, a local rear end
specialist, and JonB, that if a tech can do a GM IRS swap, the
Viper is the same thing, just a Dana gear swap. No problem for
anyone in that business.

 

[jp]

I've done it twice, don't even think of trying it your self, you must know 100% what you're doing, and ofcourse have all needed tools.
First did I swap to 3.54, the best 1/4 mile was around mid to high 11:s. Had BIG problems to get traction in first and second gear and bad 60 footers (1.8-2.0).
Then I put the 3.07 back, and do now reach 10.90:s with no problems and that with 60 footers 1.50-1.6.
So my experience clearly states, when you run with more the 600 engine HP is it best to stay with 3.07.

/JP the Swede

 

[Gerald]

http://vca1.viperclub.org/ubb/Forum14/HTML/009091.html

 

[Qualitywires.com]

thanks all! I think I will leave the gear change to the experts. I just like doing some of the work myself on the car. (I can make sure it's done right).

So if I have a lot of horsepower..stay with the stock gears? Stock horsepower..go with a higher gear ratio?

 

[Marc Lublin]

AB,
The actual removal and installation of the Vipers rear end is simple. As far a installing a new ring and pinon, I left it up to a shop that specializes in race rear ends. I have never done a ring and pinon and my thought process has always been that it is more like an art form, better left to someone who really knows what he is doing. As far as track cars go, I think if you are producing a bunch of HP it might hurt you. If you primarily drive you car on the street, it is the way to go!

 

[tzoid]

You'd best verify Jason's comments indicating the similarities between the Corvette's and Viper's differentials. A very well known mechanic in my area who specializes in differential rebuilds and overhauls that I initially took my '99 diff to for a swap with 3.55 gears examined it and quickly determined that although it looked the same, the correct tooling required to open it up and change gears was different. Keep in mind that this guy has literally done hundreds of Corvettes over the years. I can't remember the specifics but it definitely was different. He's the same one who recognized the Dana 44 replacement gears as being the same p/n as the Jeep gears which led to a call to Dana/Spicer which uncovered the issue on Dana Super 44 gears for high torque applications (a.k.a. Vipers) which was covered in a previous post. Sending the unit to a well known expert like Unitrax may be a temporary inconvenience but its well worth it knowing an expert built it.

 

[jp]

So if I have a lot of horsepower..stay with the stock gears? Stock horsepower..go with a higher gear ratio?

[/B][/QUOTE]

If you Drag race your car or do some track racing...YEPP. But if you just drive the Viper on the street, will it be more driveable with 3.54
/JP

 

[MtHam ACR]

jb wrote:
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>So if I have a lot of horsepower..stay with the stock gears? Stock horsepower..go with a higher gear ratio?
[/B]

If you Drag race your car or do some track racing...YEPP. But if you just drive the Viper on the street, will it be more driveable with 3.54
<HR></BLOCKQUOTE>

How do you define 'more drivable'?

Actually, a bigger question is, WHY swap gears at all?

- One answer is drag racing.
- Another answer is optimizing for road racing.

Maybe there are other reasons that have merit, but beyond these, I'm having trouble imagining what they could be. (Is there a rival Viper in your neighborhood, and this will give you the edge?)

And I'm speaking from experience -- I changed the stock rear end in my 99 Cobra from 3.27s to 3.73. The car was a bit more crisp (a gain that I believe would be difficult to measure), but gas mileage suffered, the car ran around at higher revs, the speedometer needed to be recalibrated, and I was constantly reaching for 6th gear on its 5speed. Obviously with with the .5 gear in 6th in the Viper, sixth could become a real gear, used more frequently. But I honestly thought this mod was a waste of money.

With all the torque on tap in the viper, I just wonder what people are looking to accomplish. If it's a coolness, or some other emotional factor, it ain't worth it.

Eric

 

[Chuck 98 RT/10]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by MtHam ACR:
jb wrote:
How do you define 'more drivable'?

<HR></BLOCKQUOTE>

That's what I wonder too Eric.

But at least now I've got one confirmation of a .2 better 1/4 time. Not that I doubt Paul but I'm holding off for a few more documented 1/4 times.

 

[pauls]

Geez, it's a dana rear. It ain't brain surgery! Any number of hot rodders, stock car guys or off road truck enthusiasts do this every week.

 

[phiebert]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Chuck 98 RT/10:
That's what I wonder too Eric.

But at least now I've got one confirmation of a .2 better 1/4 time. Not that I doubt Paul but I'm holding off for a few more documented 1/4 times.

<HR></BLOCKQUOTE>

Well I'm doing mine in the next week or two. Changing from stock to a 3.55. I want to compare 60ft and 1/8th mile times. We only have an 1/8th strip here so that's the best I can do. My best 1/8th time is 8.09 and I did 7 runs all between that and 8.2 so if I break into the 7 second range with the gear change I'll consider it a success. I'll let you know what happens. The big question for me is it going to force me to make an extra shift in the 1/8th, which will make my times worse. And I already have trouble hooking up so that might even get harder to do with the gear change. So who knows! But I'm looking forward to the seat of the pants change none the less!

 

[99 R/T 10]

Guys,
I just went to the track saturday and I had to shif to 4th(I assume this is what everybody means) everytime. My car is stock except for tubes and filters. Isn't this common? Or are we talking about going into 5th?