car_nut15

iTrader: (8)

Hey guys,

So about 2 months ago I got my car tuned. The following week I took it to the track for the first time on the new setup and on the third pass broke the rear driver axle shaft. Put a new one in and took the car to the Buschur shootout 2 weeks later. On my 5th pass I broke another axle shaft (Passenger rear this time) The Boostin performance guys just so happened to be watching that pass and in the pits told me my car needs solid diff bushings. I currently have energy suspension poly rear diff bushings. Could this be my issue or is it time for upgraded shafts? The car makes about 740hp/530Tq

I am using M/H drag radials at around 15psi. What's interesting is how the shafts are breaking. Both shafts broke at the splines in the diff. What's also interesting is that the first time I broke a shaft the CV boot on the other side had popped off as well. It looks as though the diff is moving and the clamps on the boots are actually hitting the body. I'm thinking when the diff moves it puts the shafts at an awkward angle and therefore causing them to break where they do. I have a set of solid diff bushings on order but If anyone has any other ideas/suggestions that would be greatly appreciated!

Pic of the broken axle can be seen here on the first page:

https://www.evolutionm.net/forums/ev...-mani-e85.html

badev0

iTrader: (74)

I'm surprised the rear diff would be moving enough with those poly bushings to break the axles like that, but it sounds possible if they're really hitting the body. I was thinking of downgrading to poly bushings due to the noise from the solid bushings, but I think I won't.

What are your 60's? Is the car dead hooking? I would imagine its not at 15psi.

car_nut15

iTrader: (8)

Car was spinning pretty hard but everytime the shafts broke the car seemed to squat and hook a little better. 60' were all around 1.6

Im going to try the torque solutions mustache bar eliminator with the solid bushings. I really want to avoid dropping the big bucks on shafts especially if I can get away with the stockers.

StreetThisEvo

iTrader: (48)

I've broken 2 rear driver side axles. I have all of the Buschur rear diff supports and it is still an issue for me. I doubt it is the rear end moving that is breaking them. It is obviously the weak point. Sounds like it is time for DSS axles.

car_nut15

iTrader: (8)

How many passes did you get out of the stock shafts and where did they break? I'm pretty sure you are making significantly more power than I am.

StreetThisEvo

iTrader: (48)

I broke the OEM shaft with around 17k miles on the car with about 600 whp (maybe around 2010). I broke the replacement 'used' shaft last year with around 800 whp. That replacement 'used' shaft lasted about 2-3 years. I couldn't tell you how many passes it had on it.

I now bring a spare set with me every time I race lol. But to be honest I'll probably shell out the money and will buy the DSS axles next time it breaks.

They always break on the spline that goes into the rear diff where it connects to the cup.

fimotorsports

iTrader: (92)

I have had hundreds of launches and have only broke one rear axle. This was on a wheel hop on some terrible nitto drag radials. I tend to be easy on my launch with less then 10psi of boost on a launch, usually netted low 1.5 60 foots.

Also, if you bought a used axle it may have been abused before it broke.

zentac

Have you tried driveshaft shop axles, I use to snap standard ones for fun, upgraded to driveshaft shop and haven't had any problems since.

Boosted Tuning

iTrader: (12)

Do you guys have your Rear diff plate arranged the USDM way (incorrect) or the JDM way (correct)? Just throwing it out there.

car_nut15

iTrader: (8)

I have not re-arranged the diff plates. I got a killer deal on some DSS level 5 axles. I will also be ordering the torque solutions mustache bar eliminator with solid mounts. Hoping this will solve all my problems!