# T-Jet Rear axle/crown gear/rim ??????



## Dyno Dom (May 26, 2007)

For either Aurora or AW/JL T-jet chassis, I would like info/tips for replacement
of the rear axle, crown gear & rims regarding good spacing and gear mesh. 
I have a good assortment of tools from BSRT, JW, RTHO, Scale Engineering and a neat spacer tool by ETP, but interested in sequence, technique, etc, all input much appreciated!


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## dlw (Aug 17, 1999)

Before you start, remove the top plate.

First you remove the rear rims, then push out the axle. You can do this using either your wheel piuller or by pressing the axle onto a flat surface which will push it through the other end, or by pulling it out with pliers.

After replacing the offending crown gear, first thread the rear axle through the passenger-side first, before threading though the driver's side, place the new crown gear in position and thread the axle through it and then the driver's side of the chassis. Then gently press the axle through until equal amounts of axle sticks out each side. Then carefully press on the rims, again make sure they are evenly spaced.


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## smalltime (Jun 3, 2006)

What DLW said, but maybe a little more nuanced:

I always keep a .059 axle around for this. They come in Tycos, and I have a million. 

Chuck one up in your trusty Dremel and file down the splines, just so the whole axle is the same size. Use a sharpy to color the thing so you know what its for. 

Then you string THAT axle thru the passenger side, slip on a tiny washer or two (.015/.025 is required for an original T-Jet) and slip on the gear (it should slide on) then carefully slip it thru the driver's side hole and test. 

The goal here is to get limited side to side slop, and a good gear mesh with the pinion. Once you think you good with your settup, slide the tyco axle towards the driver's side, out of the passenger's side all the way up to the point where the washers are just staying on, slip in the real axle (the one that has been well beveled on each end) so that it buts up to the tyco axle get you alignment right and press thru to the passenger's side. Center it up and you ready for wheels.


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## Bill Hall (Jan 6, 2007)

Used or new. A good visual inspection is important for all gears. Put yer grampa magnifiers on and carefully scope them. Especially true for any plastic crown gears because they are easily doinked. This helps me weed out specimens that could be repaired or should be rejected before they waste my time.

Once I get ANY crown set in, I like to feel my way around the gear set by squeezing the mesh together and then hand rolling it across my fingertips with the teeth buried to the root. This helps me identify any unseen irregularities. By gear plate substitution I can then isolate whether it's actually the crown or the pinion. I reject anything that feels chunky or lumpy. 

For stockers, like the factory, I just use the rear wheels to control any clearance issues. As wheels move out, or axles get wider, shimming is a consideration for customs, hotter builds, or when your just trying to make "already worn out" stuff work . 

It's always best to err on the side of caution when shimming. We spend too much time removing frictions from our cars; only to give it all up by getting greedy with a rear axle set up.


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## Dyno Dom (May 26, 2007)

Thanks, good info.  Hopefully, I'm not the only one that finds the trapped rear
axle/gear set-up to be so much more difficult than an inline. :freak:
The little buggers seem to take a little getting used to. 
I believe Slotking mentioned in a post about rounding the axle ends too.
The nifty adjuster tool I referred to is .059" & available thru Balls Out Racing.
How about axles for replacement like drill blank or tungsten, such as sizes?
Does anyone enlarge chassis holes or use something similar to Loctite on
crown gear or chassis holes?? It seems that I'm just getting everything
decent, attempting the final "squish"(a good Bill Hall description) with my
wheel press and the entire rear assembly goes South.


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## alpink (Aug 22, 2010)

axle diameter is 063
drill blank 064 works real nice and tungsten is probably heaviest and non-magnetic.
on those shafts without splines some locktite or super glue will be required for high performance.


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