I'm glad for you , that the end of the rainbow is the 42 RLE and 5.38 axles. Thanks JJvw .
8HP70 and 4.0?
- Thread starter bbaldwin237
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I'm glad for you , that the end of the rainbow is the 42 RLE and 5.38 axles. Thanks JJvw .
B00mb00m
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It’s famously reliable in much more powerful vehicles and stays cool because it quickly goes into lock up in each forward gear.
I called my buddy around 6:30 this morning just to tell him how awesome his truck's 8HP is lol. He got a kick out of that.
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Not for nothing but anyone bringing final crawl ratios into a discussion about automatics probably needs to be in some other discussion.
I wonder how large a transmission cooler would have to be , to deal with the heat from continuous full converter stall if you don't consider crawl ratios at all ?
Did I say the 42RLE OD is only usable on long downhills with 5.13 gears? in stock form? Are 4.10 gears now good to go for 35s and 42RLE? No need for 5.13/5.38 axle ratios anymore?
From my perspective, it looks like you'd end up with 7 actually useable gears on road. Either you run 5.xx axle ratios and first is way too short and it shifts 1-2 right away or starts in 2nd, so you can use 8th gear on the highway, or you run taller axle ratios like 4.10 or 4.27 since both first and second are lower in the 8HP than first in the 42RLE and basically write off 8th gear to just use the 0.84 7th gear and possibly not have to worry as much about pinion angles.
Setting aside the potential driveline vibration issues, probably the way to go would be to run the shorter axle ratio to be able to use 8th on the highway and then have the 4.71 first gear for off road, which gives a better crawl ratio with a stock 2.73 low range than a rubicon with the same axle ratio and 42RLE (4.71 x 2.73 x 5.13 = 65.96 and 2.84 x 4.0 x 5.13 = 58.28)
I'll cut past the misconstruing.
Why do you care if the early gears shift quickly?
What about the 8hp doesn't require the same gearing considerations as the 42lre? If it is treated the same, then it will be an 8 speed transmission with 8 usable gears.
This is interesting, I have a 10 speed in my Yukon and love how it effortless and smooth it moves through gears. I can only imagine a 6-8 speed would be awesome in the Jeep.
Yep. I let the transmission shift wherever it wants on connector trails. If 4th gear/4low is not fast enough, I go into high range.
Now answer the gearing question.
My boring Jeep has an 8 speed. I can't find a reason why something similar wouldn't be great in the TJ.
All i said was that it would be nice if it didn't require the same gearing considerations.
I'm not bagging on the idea, it just seems like it has much of the same compromises as the 42RLE - super short gears, driveline vibes
This is what Russell from Sound German responded to me about torque management on the 8P transmission...
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Yes, same as how we'd need at least some changes between the auto and manual that were OEM.
As Rasband said yes you'll need a a new crossmember. But as stated in the first post the 8HP70 is shorter than the 42RLE... Which suggested the need for a new crossmember already. This would be a good time to add a separate crossmember anyhow. Makes dropping your skid plate a LOT easier.
Now if you've still got the stock shovel I'm sure some sort of mount could be fab to work with it.
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