Diff gears for 37's on GQ

[nosdivad15]

Hi All

I have bought some 37's for my GQ TD4.2, Turbo/intercooled

Would 4.6 gears be the best ratio to run ?

Cheers in advance Cal

[5inchgq]

Depends on what you intend to use the truck for.

Personally I went for 4.3's because I still have to run 33's daily, so it was a comprimise but 4.6's would be a better choice.

[unmass]

Hi there 4.6's will bring in particular a 35 inch tyre back to the stock 4.1 ratio on a TD42. This ratio would be a good compromise and allow you to run 35's on the road should the need arise. If your after some gears we stock 4.6's I work for

Mitchell bros motor sports in Brookvale and we ship anywhere

Regards
Brooksy

[outlawgq]

Depends on what you mainly use your rig for. If you do a fair bit of traveling & are going to run smaller tyres for this the 4.6's might wear there welcome out pretty quick. Then I'd go 4.3's & use reduction gears in the transfer to compensate the 37's when wheeling. If your going to run the 37's all the time opt for the 4.6's. 4.6's should near give stock rpm on 37's at 100klm/h maybe a little under. 4.5's suit 35' tyres but they don't make that ratio for a patrol so some opt for 4.625 others 4.375. Use a tyre ratio calc & put in the desired RPM at 100 klm/h along with the tyre diameter in mm, diff ratio & 5th gear ratio & it'll give you the speed for that combo at those revs so you can work out what suits you.

cheers.

[sidewayz]

As mentioned above,

if your not running the 37's all the time and have 33's or similar for daily duties, id look at reduction gears and leave the diffs how they are.

[Nelso]

I run 37's all the time and have 4.6 gears but I also have 85% reduction gears in the transfer. 4.6's are a good combination for me because of the transfer reduction offroad but 4.8 diff gears would be closer to standard ratios and would be a better choice if you have standard transfer gears. Mine is still about 10% over on the speedo.

[SIM79]

I run 37's all the time and have 4.6 gears but I also have 85% reduction gears in the transfer. 4.6's are a good combination for me because of the transfer reduction offroad but 4.8 diff gears would be closer to standard ratios and would be a better choice if you have standard transfer gears. Mine is still about 10% over on the speedo.

Did you check your speedo with a GPS?

From what I have see 4.3 with 35s makes the speedo accurate when checked with GPS and I thought 4.6s with 37s was the same.

[A.J.]

I run 37's all the time and have 4.6 gears but I also have 85% reduction gears in the transfer. 4.6's are a good combination for me because of the transfer reduction offroad but 4.8 diff gears would be closer to standard ratios and would be a better choice if you have standard transfer gears. Mine is still about 10% over on the speedo.

Did you check your speedo with a GPS?

From what I have see 4.3 with 35s makes the speedo accurate when checked with GPS and I thought 4.6s with 37s was the same.

You are correct, I have 4.3s and a brand new set of 35"s and the speedo is spot on. Checked with 2 GPS units, 100%, not even 1km/h out

[nosdivad15]

Ok thanks for the replies

[stevejl]

I have 4.8 in my gq and at 100km the speedo reads 98km that is on 37 treps

[nosdivad15]

Hi steve funny question your Patrol is it Blue/silver with some tricky suspension mods..?

[stevejl]

Hi nosdivad15

Yer the old patrol has a trick or two up it's sleve about 1200mm of flex from ground to tyre