Rock Crawler gears - help needed

[legsx1]

Having recently repowered my shorty GQ with a LT1 chevy, I find that I have no engine braking going down hills - having to use the brake pedal far too much even in low first

My question is should I install the 43% rock crawlers or the 85% ones.

At the moment my own thoughts are to go with the 43% ones

What are your thoughts

[Mick.]

Is it a manual and what size tyres are you running?

If it's a manual and your only running 35s or smaller then 43% should be fine.

Cheers Mick.

[legsx1]

Thanks Mick

Yes it is a manual and I am running 35's

[75 cruser]

try and go for a drive with some one with reduction gears to get an idea of ratios but i would think that 85% will be to low but the 43% would be great

[ROGQ]

couldnt you just get the 85% and use 3rd or 4th gear low range for most stuff or evan high range but at leat then when ya on a real steep incline you can be going as slow as you want and shouldnt have to worry bout foot braking

[full-boost]

whats the $$ on the 43% installed?

[nastytroll]

43% would be the best maybe the 2?% as your only running a small tyre I have 85% n run 37" with 4.11 diffs n it is realy to lowwer geared, when I had 4.88 diffs 1st gear was useless as the wheels turned to slow to climb anything
I installed my gears my self but they should cost more then $400 to fit

[charlie.baldoria]

im running 85% with 35's with 4.11 diffs in my GU and so far seems to be running fine for my needs

[legsx1]

The 85% have been quoted from Marks site as $1250 incl GST, think the 43% are around the same price.

Does anyone know where they are cheaper - Snake Racing are much the same price

[jimsaq]

The 85% reduction may be a little dearer to fit as they require slight modification to the transfer case and possibly the selector fork, not 100% sure. The lesser reduction gears may not require those mods, not 100% sure on that either.

I've got the 85% reduction in my 3.0 GU, they're a godsend. Occasionally it's mildly annoying that top speed in low range is only about 30kph but it doesn't bother me.

[WICKED]

I have 85% n run 37" with 4.11 diffs n it is realy to lowwer geared

really??

i run 68% reduction, V8 auto and have 4.3 diff gears on 37's and there is a few times i think its not slow enough. but mostly its awesome.

as one of the other blokes said get the 85% and use 3 or 4th cause ya pick a higher gear but there's nothin slower than first thats controlled.

do you ever think you might go bigger rubber?

[turps]

All depends on what you are doing with the car. I would say since your in NZ where theres mud mud and more mud. 85% gears will be to slow. Where as 43% gears are very close to hi mount speed when cars in first low. Worked very well for GQHOON on the weekend.
Where as the slower gears. When in low the first 3 gears will never be used.

[thunder]

im thinking about marks gears soon.
I had the 85% years ago in a 3.0td gu and we got them cheaper as it was a group buy..

was bloody slow but so much control

[ROGQ]

When in low the first 3 gears will never be used.

is that evan on real steep decents turps?

[Mick.]

Thanks Mick

Yes it is a manual and I am running 35's

I'd definetly go the 43% then.

I've got an auto 4.2 GQ running the GU 2.8 litre diffs and on 37s and the 83% is overkill and low range cannot really be used on the beach. First is to low for crawling in my opinion.

I've got 42s which I plan on using for comp and that is where the 83% come into there own. First gear is actually usable but still very slow. About a top speed of about 10 km/h reving at 3500rpm at a guess.

Cheers Mick.

[turps]

When in low the first 3 gears will never be used.

is that evan on real steep decents turps?

Just from knowing what speeds a std gear ratios give. I would think that for most off road work. With tyres up to 35's. You would be lacking in the tyre speed.
One of the things that is needed for the terrain in Vic and what I have seen of NZ stuff (vids). There is very little that needs 80:1 crawl ratio. Also one of the problems if using a Manuel. the rev versus speed per a gear is so short. You lose allot of flexibilities. And unless running an auto. To much momentum and/or wheel speed would be lost as soon as the clutch is pushed in to change gears.