gearbox or diff need your help???

[mrp69]

hey guys

 

my 240z has a 3.5l v8 with a supra 5 speed box in it and diff has just been changed to a r180 3.54 ratio.

 

the car is still reving very high in all gears for example in 5th gear at a 110km its reving at 5000rpm

 

what could be the problem

 

diff has been changed which i thought would of fixed the problem

could it be the gearbox??

 

any ideas need help

 

Peter

[Scoota G]

Just a couple of questions.

 

What is the maximum speed in 1st 2nd 3rd and 4th?

 

What is the Highest speed you have had the car up to?

 

Is the speedo accurate?

 

Is the tachometer accurate?

 

This will give a better picture of what is going on. Also try to find out some more information on the gearbox and if you can, who did the conversion.

[C.A.R.]

Are you positive the new diff is a 3.54?

Also, how do you know the Tacho is accurate?

 

[mrp69]

1st 40km 2nd 80km 3rd 100km

 

havent pushed it past that

 

and when in 5th on the freeway 110km 5000rpm

 

at 130km 6000rpm in 5th

 

speedo is accurate

 

tachometer im pretty sure is accurate due to the sound of the car and how loud it is

 

it might be the gearbox ratios im not sure but diff was changed

 

peter

[mrp69]

diff was purchased off 240ZR (nick off this forum)

 

how can i check the tachometer??

 

 

[Scoota G]

You can get a clip on one at most auto shops.