Offroad-Express

Are these good value?? what ratio is standard in a 1988 GQ short wheel base??
http://www.trademe.co.nz/Trade-Me-Motor ... 736996.htm

gary_in_nz wrote:Are these good value?? what ratio is standard in a 1988 GQ short wheel base??
http://www.trademe.co.nz/Trade-Me-Motor ... 736996.htm

Standard diff ratio in manual TD42 is 4.1, TB42 are 3.9, RD28-T are 4.625, RB30 is 4.375. Are a few exceptions, but thats basically it.

These aftermarket ones by Superior Eng are real low! Most people with 4.1 ratios switch to 4.6's when they add a turbo and 35" tyres to get their gearing back.

gary_in_nz wrote:Are these good value?? what ratio is standard in a 1988 GQ short wheel base??
http://www.trademe.co.nz/Trade-Me-Motor ... 736996.htm

Very good price IMO $1500 per head(thats price of ARB a loan)plus you get the low diff gears 4:88 and all set up ready to go,doesnt say if it comes with compresser.If I had the money it would be gone

4.88 gears suit auto trans best for on road use,if you have a manual trans well need to run min of 35" tyre on road,just means you'll be pulling quite a few revs at 100kph if smaller than 35's.

4.88 gears + 35" tyres + manual trans = approx 2,400+rpm @ 100kph

4.88 gears + 35" tyres + auto trans = approx 2,100+rpm @ 100kph

If they suited the GU, I would have bought them. Shoulda stuck with the trusty old GQ whereparts are soooo easy to come by

so that would mean that you wouldnt have to adjust the speedo to run 35's?? because the running gear would be running same speed as with standard diametre??

gary_in_nz wrote:so that would mean that you wouldnt have to adjust the speedo to run 35's?? because the running gear would be running same speed as with standard diametre??

4.6 gears adjust speedo to more or less correct when running 35's ,4.88 would read alittle higher on speedo than actual speed but would be closer than std gearing 4.1 which reads lower than actual.

with the 4.88 it would be approx 2-3ks out at 100kph at a guess

Shane

DaveM wrote:If they suited the GU, I would have bought them. Shoulda stuck with the trusty old GQ whereparts are soooo easy to come by

GQ and GU have the same diff head. The difference is at the outer ends.

Also with calibrated speedo my truck does about 1900 rpm at 100k's with 35.5" Simex, 4.1 difs and standard auto gearing. That is with the convertor locked.

hey, wheres a good place who does 4.6 ratio gears for the diffs??
fitting a turbo and 35's soon, but want to keep gearing as close as possible to standard