Outer Limits 4x4 Board

This is a bit off topic but emphasises the need for a good tailshaft.

A friend of mine just put a Lexus V8 into a Datsun 260Z. As you would expect there was a lot of custom stuff required. He has used the Lexus auto box, Wolf 3D computer and had a custom tail shaft made. The tail shaft cost him $750 (fitted) because the original output of the Lexus box had a 'rubber doughnut thingy' which required parts to be machined to accept it.

The vehicle has done a total of 64 km since install. All of these were on the dyno excpet for loading and unloading from the trailer. The tail shaft was installed using odd types of bolts. Two with no shank at all and two with shanks too small to be of any use (getting to the point).

Anyway the tail shaft let go on the dyno last week and caused a heap of damage. The tail shaft broke, broke the auto bell housing, broke the rear off the gearbox, broke the shifter assembly, park brake assembly and put a few big cut right through the floor. It was luck it happened on the dyno because if anyone was sitting in the back they could have been seriously injured. The lap top that was in the car at the time programming the computer had it screen mounts broked because the car jumped so violently on the dyno. It has done some minor damage to the dyno also but really just some dings to the floor grates. The guy working on the dyno had the crap scared out of him too.

There have been some posts here by people who have experience with tail shafts and I would be keen to hear people opinions over who you would consider to be accountable for the damage. It have done a lot of damage to the underside of the car. Probably a couple of grand damage all up.

if there was a fault with the tailshaft then the guy who made it should cough up some $$$

but then again you were running it behind a v8 in anger...

In the application it was being used for it would seem like its one of the hazards of a heavily modified car.

The Tailshaft could be faulty.
Some of the bolts may have been faulty.
It may have just happend, no fault, just let go.


Take it to another experienced tail shaft place and get their opinion on what they think let go first and where, and what was the probable cause. If its found to be something faulty on the shaft itself then you head back to the people who made the shaft for you.

Good luck!

Not my car. Just a friends. The vehicle was delivered to the company who made the shaft with the engine and trans already in the vehicle. They did the manufacture/measure/install of the shaft.

Cheers

auto_eng wrote:Two with no shank at all and two with shanks too small to be of any use (getting to the point).

I think I'd be looking a lot closer at these items..... where exactly did it let go, and why was there no tailshaft loop fitted to such a heavily modded car ??

I saw a Trans Am traveling down Frankston / Dandenong road back in 1985 ..... the shaft let go @ 100kph and the "acrobatics" were horrifing to say the least, I was less than 50 feet behind him when it happened and my RT 6 pak Charger copped sever of damage from the debris....... wish video cameras were around then !!!

The driver of the Trans Am walked away but the car was totaled.

The Great Gonzo wrote:if there was a fault with the tailshaft then the guy who made it should cough up some $$$

but then again you were running it behind a v8 in anger...

I run stock toyota tailshafts behind a V8 with a lot more anger than he ever would. I wiould be back to the installer with a big stick and no lube!!

What was the tensile strength of the bolts?

bj on roids wrote:

The Great Gonzo wrote:if there was a fault with the tailshaft then the guy who made it should cough up some $$$

but then again you were running it behind a v8 in anger...

I run stock toyota tailshafts behind a V8 with a lot more anger than he ever would. I wiould be back to the installer with a big stick and no lube!!

I guess it depends a bit on what the guy was after from his tailshaft, was it an alloy unit, could have been dinged during the unloading from the truck ... where did it actually let go ?? in the middle at the gearbox ??

I would get is sused by another competant shop and get their opinion, If the said it was a dud from day 1 I would approach the shop that built it and ask them wha they thought .. they may be willing to come to the party with repairs to their product, but I highly doubt that they would have anything to do with the vehicle ...

Tail shaft was a steel unit going to a IRS rear so it should not have been hit during loading /unloading. The trailer used was fifth wheel job with ramp extensions for loading very low sports cars.

My suggestion was to go to the company who made the tail shaft and ask them to replace it for free and take the rest of the damage to his vehicle and dyno ect on the chin. Better to get something than nothing.

All parts have been retained, bagged and sealed. I don't know which end gave out first, front or rear.

As mentioned, sometimes things just happen.

My suggestion is get a 7MGE/GTE auto g/box, take the Lexus box and 7M box to a reputable auto tranny place, get both stripped, use back 1/2 of the 7M box aswell as 1/2 the internals (all the same except the output, which i am getting to), put 7M internals and output shaft into Lexus box.....reason for this being the 7M output shaft is ur normal run of the mill toyota auto splinned output, no fancy shock absorbing rubber mounting fot the propshaft. Ive seen this done a number of times on 1j's and 2j's (1J's and 2J's came with the big rubber thingo aswell). There is a place in Smithfield, Sydney that does all this for $500. the latest one was an MX83 cressida which we stuck an auto 2JZGTE into, and did the above g/box fiddlings without any dramas, advantage being the original MX83 prop shaft bolted in.

This way, you can use the diff end flange off the 260z, g/box end spline over, whatever unis you want and a descent tube, all custome and 99.9% wont break like ur mates one did

Phill