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Well, the old T5 finally gave up the ghost... The rear mainshaft bearing is wasted, it was making such a horrendous racket when in 5th gear that I had to drive it all the way home from Mojave in 4th. There were some p'ed off truckers! I took it apart and the damage after 210k on it is pretty extensive. Both ends of the mainshaft are messed up (output splines and input/4th gear), all the bearings are wasted, synchros are mostly chewed up with the exception of 3rd/4th, and the reverse gear and idler have pretty gnarly damage on the engagement side. I added it all up in a very nitpicky fashion (if it looks messed up, throw it out), and I'm up to about $850 for parts at 4wd Hardware pricing. I know that's on the high side, but I am thinking maybe it's time for an upgrade. Here are the options:
The obvious choice is rebuild the stock one. Cost: ~$850. Downside - same weak tranny which will only be worsened by a 4 to 1 tcase.
Swap in NV4500. Expensive adapters ($750 with bellhousing so that driveline is not 4" longer), awesome 1st gear (5.61 sounds good to me), and a possibly too tall overdrive for my 4.56 axle ratio. Possibility that I would skip a 4 to 1 on the tcase makes this somewhat attractive, since with the stock D300 I would have a crawl ratio of 73.2. I would have to find a pretty cheap junkyard tranny to make this my choice, which is not likely since I have been saying I'm going to get that York out the jyard for six months now... Cost: $750 adapters, $500? - $1700 tranny. Total: $too much
Swap in T18. I eliminated this thought faster than it came into my mind. I must have overdrive. Moab here we come...all 1500 miles of it.
Swap in AX15. Debatable strength advantage over T5. Cost: $too much for what you get.
Buy a rebuilt T5. Cost: ~$500-$1200. Bad idea. I'm sure some places slap new bearings in them and call it good.
Buy a new T5 Jeep World Class. These guys www.5speeds.com have new (not rebuilt) T5 WCs with roller bearing 2nd and 3rd gearsets (stock only 1st is roller) with Timken countershaft bearings (stock is roller without thrust control), and a countershaft rear bearing reinforcing plate. I talked to them and they say that this tranny is better, but still not up to taking tons of abuse due to the inherent limitations of the gear design (4.03 to 1 1st gear makes for some high torque loads) and the aluminum case. Cost: ~$1400. Simple, drop in replacement.
Buy a new T5 WC with G-Force gearset. The same guys that make the Jeep WC above also make gearsets with gears that are much beefier and have a shallower helical cut (less thrust load). Uses HD 26 spline input shaft, so a new clutch disk is required (no biggie, planning on replacing it when the stroker is done). The big disadvantage here is gear ratios. They build these primarily for cars, so the ratios are 2.94, 1.94, 1.34, 1.00, 0.80. This is a problem. The only way to get a respectable crawl ratio is with major regearing on everything else. With an Atlas 5 to 1 and 4.88 axles, the ratio is only 71.7, the same as a stock T5 through 4 to 1 tcase. The cost here is prohibitive. Cost: $1800 tranny, $2200 tcase, $300 axle gears. Total: $Insane
Since I am not only cheap, but also an optimist, I have decided to buy the T5 WC stock ratio tranny new from 5speeds.com and hope I don't break it. Since I did not grenade the stock T5 and most of the gears are in good shape, I think that driven reasonably this tranny will be a sufficient upgrade from stock. This is not much more money than the parts to rebuild mine, and the best part is I don't have to do it. Obviously, I am in need of a 4 to 1 kit for the D300 so that is next. My crawl ratio will be a respectable 73.5. I figure if I break this tranny, I can buy another one and still spend less than what some of the other options cost.
Of course, if somebody has an NV4500 laying in the garage and they are giving it away, please let me know.
:shades:
Rick
The obvious choice is rebuild the stock one. Cost: ~$850. Downside - same weak tranny which will only be worsened by a 4 to 1 tcase.
Swap in NV4500. Expensive adapters ($750 with bellhousing so that driveline is not 4" longer), awesome 1st gear (5.61 sounds good to me), and a possibly too tall overdrive for my 4.56 axle ratio. Possibility that I would skip a 4 to 1 on the tcase makes this somewhat attractive, since with the stock D300 I would have a crawl ratio of 73.2. I would have to find a pretty cheap junkyard tranny to make this my choice, which is not likely since I have been saying I'm going to get that York out the jyard for six months now... Cost: $750 adapters, $500? - $1700 tranny. Total: $too much
Swap in T18. I eliminated this thought faster than it came into my mind. I must have overdrive. Moab here we come...all 1500 miles of it.
Swap in AX15. Debatable strength advantage over T5. Cost: $too much for what you get.
Buy a rebuilt T5. Cost: ~$500-$1200. Bad idea. I'm sure some places slap new bearings in them and call it good.
Buy a new T5 Jeep World Class. These guys www.5speeds.com have new (not rebuilt) T5 WCs with roller bearing 2nd and 3rd gearsets (stock only 1st is roller) with Timken countershaft bearings (stock is roller without thrust control), and a countershaft rear bearing reinforcing plate. I talked to them and they say that this tranny is better, but still not up to taking tons of abuse due to the inherent limitations of the gear design (4.03 to 1 1st gear makes for some high torque loads) and the aluminum case. Cost: ~$1400. Simple, drop in replacement.
Buy a new T5 WC with G-Force gearset. The same guys that make the Jeep WC above also make gearsets with gears that are much beefier and have a shallower helical cut (less thrust load). Uses HD 26 spline input shaft, so a new clutch disk is required (no biggie, planning on replacing it when the stroker is done). The big disadvantage here is gear ratios. They build these primarily for cars, so the ratios are 2.94, 1.94, 1.34, 1.00, 0.80. This is a problem. The only way to get a respectable crawl ratio is with major regearing on everything else. With an Atlas 5 to 1 and 4.88 axles, the ratio is only 71.7, the same as a stock T5 through 4 to 1 tcase. The cost here is prohibitive. Cost: $1800 tranny, $2200 tcase, $300 axle gears. Total: $Insane
Since I am not only cheap, but also an optimist, I have decided to buy the T5 WC stock ratio tranny new from 5speeds.com and hope I don't break it. Since I did not grenade the stock T5 and most of the gears are in good shape, I think that driven reasonably this tranny will be a sufficient upgrade from stock. This is not much more money than the parts to rebuild mine, and the best part is I don't have to do it. Obviously, I am in need of a 4 to 1 kit for the D300 so that is next. My crawl ratio will be a respectable 73.5. I figure if I break this tranny, I can buy another one and still spend less than what some of the other options cost.
Of course, if somebody has an NV4500 laying in the garage and they are giving it away, please let me know.
:shades:
Rick
Dave
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