Drivetrain Play

[SharpesGarage]

Hi All - new Viper owner here. I have enjoyed my time reading lots of past posts learning about the Viper and it seem there are a ton of knowledgable folks on here.

I got a 94 back in August and have enjoyed driving it, now that it is winter here i want to address some of the issues with it.

The biggest issue i am having right now is a lot of driveline play. On accel and decel there is a huge amount of jerkiness to the car. To the point where i really have to manage the clutch to keep it from clunking around, particularly at low speeds on and off throttle. I thought for sure it was bad ujoints but that does not seem to be the case.

I took the video below showing the slack in the driveline as i wanted to check the ujoint and diff, both of which don't seem to be the issue?

- The car has 84k km (~50k miles), stock motor and trans mounts (both ordered and will be replaced with Poly)
- There is no whining from the rear diff.
- The trans has popped out of 3rd gear 2-3 times when in gear and decelerating, but no issues shifting into any gears. New clutch installed a year ago by the previous owner.

Is this amount of play in the driveline normal? I find it really tough to believe the mounts are causing such excessive play and jerkiness? Is that amount of in gear clunking normal?


https://www.youtube.com/watch?v=s6OSEvQk2KM&t=17s

Appreciate the support

[Old School]

That's a normal amount of gear back lash. Was the trans in gear in that video?

[AviP]

Very interesting video. I haven't tested my 97 the way you did but have had most of the low speed symptoms you describe since brand new. When I asked the dealer back in the day, I was told that was normal behavior and tolerances. It's possible that the play has increased over time due to bad shifting by the previous owner. Mine has not exhibited any change in play since brand new. Also, I do not have the described symptoms at speed.

[Viper98]

Hey Sharpes, nice ride! Congrats and welcome aboard!
I’m gunna guess here— stock rear? If it has stock rear gears you are probably ok. My ‘98 has stock gears and bucks at low speed in 1st and 2nd gear, and anything higher, obviously. Of course, this is at lower speeds, like going through a neighborhood, etc.
I have read threads here where that is normal and how it goes away once different gears are swapped in...3.23, 3.55, 3.73, etc
And as stated above, there is a certain amount of gear lash, but can be “tightened-up” by swapping in different gears.
As far as the 3rd gear popping out of gear, I guess it is possible that some “spirited” gear banging may have chipped a tooth. I don’t know I’m not a tranny guy. However, you did mention a new clutch install.
These trannies are supposedly very hardy. I’m thinking you’re good.

JM2C

Hope the best for ya, bro

[GTS Dean]

Gen 1s can have bucking problems due to the twin throttle cables out of synch. I cannot recall the details on adjustment, but it is pretty easy to do.

[My98RT10]

Looks all normal to me.... and yes, Spicer components are factory.

As GTS Dean says, if you have a lot of bucking that might be caused by the throttle cables rather than the drive train slack. That being said, Gen1/2 Vipers are somewhat "sensitive" at low speeds... In any case, check the throttle synchronisation to rule this out.

[Horsepower junkie]

Have a 94 had same problem. Synched the throttle body cables and helped a lot. Should be able to find the instructions on this site. On my 94 and 97 backlash is normal. Helps protect rear end and trans.

[SharpesGarage]

Wow thanks for all of the quick comments. This is more re-assuring for me that it doesn't appear to be major.

I'll report back once the mounts are in and I have a chance to adjust the throttle cables, i never would have considered that one.

3.55's are on the list to do this year

[Fatboy 18]

Worn engine mounts and worn transmission mount can help with bucking. I couldn't see what your half shaft joints were doing in that Video particularly where they meet the back of the wheel hub. Spicer UJs are the correct UJs but they are solid UJs designed specially for the Viper so they do not have a grease point. The Spicer UJ Straps stretch to shape when fitting them so ideally you should replace the straps each time, the bolts have a Loctite patch on them, the bolts can be reused as long as you use Loctite during reassembling. UJs and Engine mounts are available from Vendor Site sponsors here such as JonB Partsrack or check out Rock Auto. I don't know why but I have gone through 3 half shafts and UJS 60k miles.


https://www.youtube.com/watch?v=m-fI3B7tRCU


https://www.youtube.com/watch?v=XpLKyjBz5O4

[Grcforce327]

Just for info, always remove the driveshaft to check u-joints properly. Also, while the shaft is out, check wear on the yoke splines.

[dave6666]

Never deccelerate.

^^^ this

[Lalmeida617]

Everything you show there looks very similar too my 96RT. I think your lash is normal. Chuck Tator looked at mine a couple years back and said it was good. I do get the jerkiness you mentioned above. Does it get better when the car is hot? When my car is cold it is hard to keep it from bucking. Syncing the throttle cables can sometimes help. It clears up once hot. Syncing is easy to do just read your manual or watch the vid someone posted above no tools required. My next question is, is there any noise? Clacking on takeoff?

[SharpesGarage]

Thanks all, i took a look in the manual on how to sync the throttle bodies and it is pretty straight forward.


Does it get better when the car is hot? My next question is, is there any noise? Clacking on takeoff?

hot or cold, doesn't really change. As long as the drivetrain is loaded there are no noises, it is only when coming on/off load. It sometimes will make a clank when starting into reverse, but from what i've read around here that is fairly normal?

[ViperC]

Mine seems to have similar symptoms and I did the wheel test like you did and it seems to make the same clunking noise near the trans.

[SharpesGarage]

Quick update, replaced the motor mounts and transmission mount with poly units from Partsrack. This has helped a lot and the jerkiness is improved at low speed. Need some warmer weather to go out for a drive.

The throttle cables were slightly out of adjustment, not opening all the of the way and the passenger side first. I've made it so the drivers side slightly opens first and opens right to the stopper but the passenger side cannot be adjusted enough to open all the way. Is it common for the cables to stretch? It seems there is only an adjustment on the bracket for the drivers side (front to back) and the passengers side is fixed to the intake manifold.

[Steve-Indy]

Cable CAN stretch...which I solved by putting a short spacer ( actually a short, split collar) that I crimped around the cable at the very end which effectively shortened the cable. I achieved a considerable gain in seat-of-the-pants performance by fully opening the throttles.This fix is still working 20 years later.

[SharpesGarage]

Good idea, i think that will be the ticket for me to add back the appropriate amount of adjustability to get it to open all the way. Maxing out the adjustor only gives me 80-90% of full throttle for the passenger side.

[Steve-Indy]

I put together a small box with battery, red (port) and green (starboard) lights, a long cord, and 2 micro switches. I mounted the micro switches in a way that they closed at 100% full throttle...thus illuminating the lights at 100%. This allowed me to work the gas pedal and still know what was going on with the throttle bodies when I was working on the car without an available helper. Of course, this was used for engine OFF testing only.

[SharpesGarage]

Good idea. I've been mounting a camera and recording the actions of the throttle body. That way i can also watch in slow motion for which one opens first.

[Steve-Indy]

Ahhh...the difference 20 years makes !! :)