differential of my 97

mike4533

Enthusiast
Joined
Mar 1, 2023
Posts
2
Reaction score
0
Location
Suisse
Hello everyone,

i have to disassemble the differential of my 97 viper gts in order to change it to 3.55. it has 25000 miles. do you have any technical data sheet on disassembly and reassembly or video to change this Differential ratio?

do i have to change the radial shaft seals or screws? is there a parts kit for this change? thank you for your advice
 

Steve M

Enthusiast
Joined
Dec 29, 2011
Posts
1,078
Reaction score
207
Location
Dayton, OH
If you do the work yourself, I'll warn you in advance that it is time intensive, and requires some specialty tools that you may or may not already have on hand.

Due to the time and effort required, I would recommend replacing all bearings and seals while you are in there. You'll be extremely upset if you have to pull it back out because a seal started leaking.

I'm not sure what screws you are referring to. The big items like the carrier bearing cap bolts and differential cover bolts can most certainly be reused. Half shaft and driveshaft u-joint bolts/straps should be replaced.

I made a pretty detailed write-up for the Gen 3/4/5 crowd here that might be worth a read:


The Gen 1/2 differentials are different, but a lot of the information should still apply.

I quickly searched YouTube, and there are a couple of videos that have some good content related to removing and replacing a Gen 1/2 Viper differential, but did not specifically address setting up a new ring and pinion - that's the part that is a lot more involved, and requires time and patience to get it right. If you get it right, the differential will be quiet and last a long, long time. If you don't, you can quickly trash gears and/or bearings and have to start all over from scratch. It's a job that requires attention to detail. Experience is the only way to speed up the process.

Master install kits exist, but don't include some small odds and ends (like the output shaft support bearings) that you may want to replace. You can generally piece together your own install kit and save some money if you are so inclined. You'd want to disassemble yours first and grab the part numbers you need off of the existing stuff in order to do that.

The factory service manual should have all of the specs (bearing preload, backlash, and torque specs) you'll need. Hopefully someone that has access to one might be willing to share that information with you here.

Hope that helps at least somewhat.
 

Goggles Pizano

Enthusiast
Joined
Nov 25, 2009
Posts
356
Reaction score
79
Do you realize how your post was inappropriate?
Nope but if that pissed you off then read the following which is still in the uninappropriate level: Please enlighten us on how you can't look through and read your service manual to find the section you are interested in.
 

BoremViper97

Enthusiast
Joined
Jan 21, 2023
Posts
74
Reaction score
14
Location
Warm climate of America
Nope but if that pissed you off then read the following which is still in the uninappropriate level: Please enlighten us on how you can't look through and read your service manual to find the section you are interested in.
I’m not pis ed off. Not at all.
I’m laughing that I found the pathetic loser on this forum who enjoys trolling people for an innocent comment.
I’ve been on a few forums and there’s always one.
Found ya!
 

Steve M

Enthusiast
Joined
Dec 29, 2011
Posts
1,078
Reaction score
207
Location
Dayton, OH
for Christmas gift my wife got me an original service manual. I wonder if it has a section of how to disassemble and reassemble the rearend
I’ll share my own experience with the service manual, but keep in mind that the electronic version I currently have in my possession may be quite different from what you received for Christmas.

The 2010 service manual I was gifted a few years back from another Viper owner has a pretty comprehensive section on servicing the differential. For the most part, provided you had enough experience, you could muddle your way through a differential rebuild, but it is missing some key pieces of information that only experience can possibly fill. There are also some procedures that are only possible with the full set of factory service tools, many of which are either not available or are so prohibitively expensive that puts it beyond the reach of your average shade tree mechanic.

On the positive side, it is a highly useful reference for the various specifications (torque specs, backlash tolerance, etc.):

You must be registered for see images attach


It also has a comprehensive list of different special service tools, including drawings and part numbers:

You must be registered for see images attach

You must be registered for see images attach


The part numbers are the most useful, as some of these can still be found on Ebay, some more loved than others.

There are, of course, limitations to the information provided. As one example, this is how they suggest removing the inner pinion bearing using the OEM recommended tools:

You must be registered for see images attach


A quick Google search found the Puller Press (C-293-PA) for anywhere from $319 ($249 + $70 shipping on Ebay) to $498.96 (Mopar Essential Tools and Service Equipment). The Puller Block Set/Adapters (C-293-47) were slightly more reasonable at $97.98 (Ebay), but were out of stock on some other websites. They certainly appear to be the correct tools for the job, but there are more cost-effective options like a clamshell bearing puller that can do an equally good job at a much lower price point:

You must be registered for see images attach


As another example, this is how they recommend removing the output stub axle shaft seals:

You must be registered for see images attach


I was able to pick up the seal remover tool (7794A) for ~$90, but keep in mind that I already had a compatible slide hammer. Unfortunately, it looks like they have gone up in price significantly since. There is currently one on Ebay for $221.95 (OBO), but it has clearly been damaged. Regardless, that is the best tool for that specific job, but they leave out one critical piece of info: before going to town on the seal with a slide hammer, you first need to take a pair of heavy-duty diagonal cutting pliers (a.k.a. ***** or dikes) and snip the seal’s tension spring – otherwise, it is extremely difficult if not impossible to remove. This is where some experience is required to fill in the gaps.

There are plenty of useful diagrams:

You must be registered for see images attach

You must be registered for see images attach


But there are also some things that you will likely never be able to use, like the pinion depth diagram and variance chart:

You must be registered for see images attach

You must be registered for see images attach


That chart could be incredibly useful, but only if the variance is marked on your new ring and pinion set. None of the new-in-box ring and pinion sets I’ve received (3.73, 3.55, and a fresh set of OEM 3.07s) had this etched on them, so that is likely something you’ll never encounter again. That would likely have been common while these cars were still in production, but obviously that is no longer the case, so you’ll have to start from scratch when it comes to selecting a new pinion shim.

The manual does confess that it only has some general information, like for generating and reading gear contact patterns:

You must be registered for see images attach

You must be registered for see images attach

Solely relying on those diagrams will only lead to serious confusion, especially if you don’t know that an ideal pattern for an OEM 2-cut gear set may actually look something like this (this was from a set of Dana Spicer 3.73s):

You must be registered for see images attach


One example where this “general information” could really bite you is with applying RTV silicone sealant to the differential cover:

You must be registered for see images attach


They are missing one critical piece of information in step 1 – you also need to apply sealant to the tops of the carrier bearing caps, as it fills the small gap between the caps and the supports on the differential cover. Again, only experience (and a little RTV) would fill in that knowledge gap.

That said, I’d still rather have the service manual than not. You just have to keep in mind that it was written for the average service tech that will typically only do a full R&R with an already fully built replacement unit, or only have to do small things like replace the seals. Setting up a new ring and pinion would be beyond the abilities of most, as they would likely just reuse the old shims and assume that the differential case itself is what determines the correct shims rather than the ring and pinion set. In my limited experience, the individual ring and pinion sets will dictate the proper shims – the ones I’ve set up used vastly different shim thicknesses than what were originally there to get everything where it needed to be.

Your mileage may vary, but I hope that you’ll find at least some of this information useful.
 

Goggles Pizano

Enthusiast
Joined
Nov 25, 2009
Posts
356
Reaction score
79
I’m not pis ed off. Not at all.
I’m laughing that I found the pathetic loser on this forum who enjoys trolling people for an innocent comment.
I’ve been on a few forums and there’s always one.
Found ya!
Yep you are 100% right I'm a loser, but I do know how to open and read a book and not post a completely useless post.
 

Forum statistics

Threads
153,307
Posts
1,682,815
Members
17,824
Latest member
J_boguejr
Top