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HIGH RPM V8 and Patrol G/Box

Posted: Mon Apr 12, 2010 4:50 pm
by OPBUNDY
Hi All,looking for some feedback.

Has anyone had or got any experience with coupling a GQ TD 42 Gear box to a hard revving V8, with regard to gear shifting.
I have an engine(V8) which will charge to 7500rpm the concern is what will the gearchange be like.

In the past i have run a 350 chev in a patrol that revved hard and the gearchange was hopeless at any engine speed above 6500 rpm.

This is an Offroad Racing application so good gearchanges are vital and high engine rpm are common.

I would really like to stay manual but if the big Patrol box cannot handle high engine speed then Auto it will be.

Any input would be great

d

Posted: Mon Apr 12, 2010 7:52 pm
by Clanky
Dont know about the fit into your car, but maybe look at a GU box internals as my manual says they have double synchros.
Maybe someone else can shed more light

Posted: Mon Apr 12, 2010 8:39 pm
by Chook350
i was lucky enough to be working over easter at a state offroad round here in vic, having not been around weapons like this before i was amazed the amount of autos that were in the field. Personally i love manuals, to the point i hate my daily driver lol.
I think a well built auto manual valve body is the way to go for your application

Posted: Tue Apr 13, 2010 7:31 am
by 351ciofgrunt
Get a manual box out of a GQ later than 1994, I've heard that these ones shift a lot better at high revs than the ones before 1994.

Maybe someone else can confirm this.

Posted: Tue Apr 13, 2010 8:39 pm
by fnqcairns
351ciofgrunt wrote:Get a manual box out of a GQ later than 1994, I've heard that these ones shift a lot better at high revs than the ones before 1994.

Maybe someone else can confirm this.
Someone can correct me but I have the GQ2 which has a few differences over the earlier ones. One of those is supposed to be the GU updated gearbox, different ratios to previous GQs...there may be other changes closer to GU as well in these boxs.

n

Posted: Tue Apr 13, 2010 9:02 pm
by Clanky
My GQ and GU info show the TD42 box ratios to be the same.
Its not clear on whether the updated double synchros came in the late GQ's or not - but definitely in the GU

Posted: Wed Apr 14, 2010 3:44 pm
by PGS 4WD
It's a big heavy truck box, don't expect miracles in regards to shift quality, most at 6000 rpm are ordinary when trying to upshift quickly, especially second to third, worse in low range too.

Joel

Posted: Thu Apr 15, 2010 10:34 am
by OPBUNDY
Thanks for your input guys, looks like I wil be leaning towards a Manual valve body auto.
Thanks for the replies.