First and foremost - I DO NOT GO 80mph in my EV Jeeps or any other Jeep. The ONLY reason I know it can go that fast is it does it so silently and without the ICE feeling of sound and vibration to give you any indication of the effort, I looked down once and it was off the speedometer 85MPH mark and the GPS speedometer I put in to get a better reading of actual MPH read 82, 83, 84mph.
My new mental gauge is looking around on the highway and wondering why everyone else is going so slow....
Danger Will Robinson, DANGER!
Other than the occasional 70mph passing, I try to keep it under 65mph on the highway.
Now, on to your root question - wear and tear on the connective parts.
The Dana motor has an output shaft that connects to the input shaft of the various transmissions. We custom make that, here's some pictures of it:
View attachment 705278
In our configuration, the coupler is hard fixed to the motor shaft BUT the splined side is lose to the transmission input shaft. This allows for the tiny amount of transmission center spline movement (normal) and was where we were worried about it causing any wear.
On our test Demo Jeep, we've torn the TAC (Torque Adapter Cover) down about 12 times. Now approaching 9k EV driven miles.
I assumed I'd see some of that grayish slurry at the bottom of it, hopefully showing only mild signs of contact with two interacting and rapidly rotating parts.
BUT, to my complete surprise, it never presented. Nothing. The small amount of weep from the transmission into the TAC, were the coupler lives and spins away, nothing, not even a hint of gray or any feeling of grit.
So, that's external of the transmission, now to the internal of the transmission...
At about 4k miles, I decided to take the transmission out and have it rebuilt. Not for any reason, it just seemed stupid not to have a baseline of rebuilt 'new'.
My interest was in the 2nd / 3rd synchro and specifically the brass thrust rings, the ones that cause the spinning shafts to slow to a point that synchro mesh is allowed to do it's magic. My logic was that these were and are the most wearable parts by design, They should reflect any additional wear or any excessive wear, especially in the thin thread-like inner part that's designed to use friction to slow the rotation down.
Again, 100% surprised that the stock transmission not only had no excessive wear, it had no decolorization, a symptom of heat when they wear OR are pushed hard to engage from gear to gear. Nothing.
I send all my rebuilds to Box and Gear - Yes, yes, I know, you're thinking Box and Gear is probably a dating bar, I mean, sure, I was hoping it was but, no, just gears and gear boxes.
Sad,
But, Jessie, the owner's son and chief over there was likewise very happy with the rebuild and the lack of wear at any of the stock transmission wear points.
I worry and worry about parts I can't see, like these. But, so far, ZERO wear and tear on the stock parts or the adapter / coupler parts.
Color me surprised.
Here's a snap of the Motor Cradle Assembly (MCA) being pulled out during one of those early inspections.
View attachment 705279
Lastly, here's my RPM to MPH chart for the T176 Transmission (not a TJ transmission):
View attachment 705329
That's for 3rd gear. If I hit 5000rpm, I think the Jeep would simply explode at 95mph...
Even in 2nd gear, it's not an excessive load on the ICE running gears:
View attachment 705333
Additionaly, I lock out the Dana motor from anything above 6000rpm, as a precaucation. This can be removed by the end customer but that's how we ship them.
That motor, by the way, has a max of 10,000rpm.
Hope this comes close to answering your question.
- Patrick
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