Hello All,

We're about to bit the bullet hard after trashing our D30 in a competition and order some Dynatrac Pro Rock 60's and I have a few questions. Before you all start flaming about building junkyard stuff, please note I'm in the UK and don't have access to the kind of seconds you guys do...

Platform is a CJ7 with TH400 and quadratrac.

What we are planning on doing is getting the Pro Rock 60s front and rear with 4.88 gears, ARBs, 35 spline, hi-steer. Ultimately we will be running aggressive 36" tires yet TBD. Down the line (once we get more money) we will be swapping to coilovers.

We run primarily mud competitions/winch challenges much like the Malaysia Rainforest Challenge, Outback Challenge, Croatia Challenge, etc. To date we've run some events here in the UK as well as Portugal. The reason for the rebuild is that in our last event we trashed the D30.

So enough background...here are the questions:

1. We would like to run 1350s. Will there be any clearance issues on the front driveshaft with the quadratrac front output running so close to the TH400? Our choices are 1310, 1330, or 1350. Jess, whatcha think?

2. With these new axles, what do you think the new weak link will be? I tend to think the chain on the quadratrac will be but if this is regularly changed out I don't think it will be a problem.

3. Being that these axles are cha-ching, we are trying to decide what options are worth going for. For example, the extra oiling at only $120ish is kinda a no-brainer to get. What about full floating at $700ish? Being that we've not had problems with the 20, I can't see spending the cash. What about gundrilling or fluting? I think both of these are about 700 as well. The key thing here is cost with max return. Are there any options that you see as a must have?

Thanks in advance.

Here's a pic of where we broke the 30. We blew out some teeth on the ring gear and smoothed the pinion gear, destroyed the ARB and corkscrewed the driveshaft. We made it up on the third try but got a DNF shortly after as we couldn't continue on and ran out of time.

Pic (http://www.darksiderz.co.uk/gallery/view_photo.php?set_albumName=1978CJ&id=nationalwinchbigair)

BTT for Monday crew...

Originally posted by SniperFire
Hello All,

We're about to bit the bullet hard after trashing our D30 in a competition and order some Dynatrac Pro Rock 60's and I have a few questions. Before you all start flaming about building junkyard stuff, please note I'm in the UK and don't have access to the kind of seconds you guys do...

Platform is a CJ7 with TH400 and quadratrac.

What we are planning on doing is getting the Pro Rock 60s front and rear with 4.88 gears, ARBs, 35 spline, hi-steer. Ultimately we will be running aggressive 36" tires yet TBD. Down the line (once we get more money) we will be swapping to coilovers.

We run primarily mud competitions/winch challenges much like the Malaysia Rainforest Challenge, Outback Challenge, Croatia Challenge, etc. To date we've run some events here in the UK as well as Portugal. The reason for the rebuild is that in our last event we trashed the D30.

So enough background...here are the questions:

1. We would like to run 1350s. Will there be any clearance issues on the front driveshaft with the quadratrac front output running so close to the TH400? Our choices are 1310, 1330, or 1350. Jess, whatcha think?

2. With these new axles, what do you think the new weak link will be? I tend to think the chain on the quadratrac will be but if this is regularly changed out I don't think it will be a problem.

3. Being that these axles are cha-ching, we are trying to decide what options are worth going for. For example, the extra oiling at only $120ish is kinda a no-brainer to get. What about full floating at $700ish? Being that we've not had problems with the 20, I can't see spending the cash. What about gundrilling or fluting? I think both of these are about 700 as well. The key thing here is cost with max return. Are there any options that you see as a must have?

Thanks in advance.

I don't know what to tell you on the output yoke, but I can tell you that if you are going to drop the coin on pro rock 60's, do it right the first time, and go full floaters.... fluting and gundrilling I don't see as necessary, but a nice added bling bling if you can spend the cash. If you are going to go as far as swapping out to pro rock 60's, I would ditch that pos quadratrac t case, and throw a D300 t case in its place. Do it once, do it right.. Or in my rigs case, Do it 3 times, do it right :rolleyes:
Scott

The transfercase issue is a problem - I think 1310 is the best thing on that application becuase of the room- even though it would be good to run larger stuff - so its a catch 22 - Jess