Building a Universal Modified

I've been driving BAM BAM to work every day for a couple weeks except for yesterday when I had to get my wife and take her to work after hitting here second deer in a month:



... she is ok. The deer didn't stick around for an interview.

Those newer Jeep are not as tough as Bam Bam.Glad to here your wife is ok.

Lee (MN) wrote: ... as the hub warms from use it gets slightly larger from expansion and the rollers in a tapered bearing will expand lengthwise not in diameter like a ball bearing, so as the hub expands the bearing looses a bit of its preload.

If the hub expands, wouldn't the bearings get tighter since the outer races are inboard? ... unless the dead shaft and hub expand equally.

2) on a “Live Shaft”, or one that turns, like an output shaft on a D-18, the shaft slightly increases in length due to heat, if you set the output shaft with preload and after the T/C warms up to it’s operating temp you will run the risk of overloading the bearing!, so if your running .004 of end play on the shaft at assembly odds are if you checked it at operating temp on a warm summer day you would find there would be little if any end play!

Why would the front hub expand with heat but the T'case box not expand? ... Why would a dead shaft not expand but a live shaft does?

.... I’ve been into many gearboxes, swing boxes and final drives on heavy equipment over the years, .004-.006 is pretty common on most every “Live Shaft” situation.

If that is how its done with a live shaft, I'll believe it, but I still don't quite understand why a dead shaft wouldn't expand or contract any more or less that a live shaft. I don't doubt you, but it isn't clicking with me. Not that it is that important

.... more changes:

first, I made some new spring brackets similar to what Metcalf posted except I added some castle tops to capture the axle perches:





.... then I put 9" bilstein shocks on the front:



These are the same 255/70 valving as the rear. The shock towers are a copy of what Metcalf did on his build but not as tall. The bottom of the shock is still attached to the spring bracket. I just don't want obviously too tall shock towers at this time. I reserve the right to change my mind on that. Truthfully, the springs will travel 10" but my geometry will not allow for that much travel without various collisions so I went with 9" to keep them as short as I could.

... also notice in the picture that I adjusted the bump stops on the front axle so that I can get the tires to turn an extra 2" each way, just shy of colliding with the springs at the rear. I'm not sure why I didn't do that a long time ago

Thanks for reading.

Edited by jpet - 05 Nov. 2018 at 6:48pm

jpet wrote: ... also notice in the picture that I adjusted the bump stops on the front axle so that I can get the tires to turn an extra 2" each way, just shy of colliding with the springs at the rear. I'm not sure why I didn't do that a long time ago

Yup, sometimes the drivetrain just doesn't like going into front dig. I think having the rear locker open sometimes helps that. Having an automatic seems to make it more possible too. Slight changes in front to rear gear ratios could cause issues too. 

If you switch to a diesel engine it will prevent the transfer case from making noise. haha! 

I believe you Lee. I’m surprised that it makes that much difference but I’m guessing it has been researched and tested.

LuzonRed47 wrote: Every time I see detail photos of jpet's Bam Bam, all his smartly engineered upgrades, I think how it must piss off the originality snobs in the MVPA....

.... it shouldn’t. BAM BAM is a Jeep made of parts. Even though the title of the thread has the word “Modified”, no actual g503s were modified in the build.

Did the Dana 18 help you out at all on this trip?