How do you know when it is unhappy?I plan on following this advice, but wonder what RPM people prefer, or what RPM makes the engine happiest?
I'm shooting for 2300-2500 RPM when cruising the highway.
How do you know when it is unhappy?I plan on following this advice, but wonder what RPM people prefer, or what RPM makes the engine happiest?
I'm shooting for 2300-2500 RPM when cruising the highway.
Never sees 75. That's too fast for my mild lift and short wheelbase.What are the engine rpms at 75mph? (Fixed)
We can help with that.Never sees 75. That's too fast for my mild lift and short wheelbase.
Well, I went from stock 31's to the 33's and didn't mind the loss of off the line performance. So from my perspective I'm going to ensure I have all the other $tuff I need and will do gears when I reach the confluence of need and available funds.It is easy to be contrary if you have never driven 33's with 4.88's or 5.13's. Had you said you had them and went back to 4.10's since you didn't mind the loss of off the line performance, that's a bit different.
How do you know when it is unhappy?
I guess I have to do that nowPut a blower on it and you won't need deeper gears
It is common wisdom to go one gear step deeper when possible to improve slightly over stock parameters due to the added weight of the larger tires.I’m just a little confused because
Stock was a 29 inch tire with 3.73 gears. If I switch to a 33 inch tire and install 4.56 gears I would still have deeper gears than stock. I thought that 4.88 or higher would possibly be excessive. I’m currently on 3.73 gears on 33 inch tires and yes I know it’s lacking power going up hills, but when I regear I thought the goal was to keep it close to stock parameters. ya I know I can probably benefit from deeper gears but I don’t want the engine screaming going down the highway.
I’m just a little confused because
Stock was a 29 inch tire with 3.73 gears. If I switch to a 33 inch tire and install 4.56 gears I would still have deeper gears than stock. I thought that 4.88 or higher would possibly be excessive. I’m currently on 3.73 gears on 33 inch tires and yes I know it’s lacking power going up hills, but when I regear I thought the goal was to keep it close to stock parameters. ya I know I can probably benefit from deeper gears but I don’t want the engine screaming going down the highway.
I have a 2004 TJ Unlimited with 205,000 miles on it. Every time I drive it I use moderately enthusiastic throttle input and it hits 4 grand in every gear up to OD. It just doesn't care.Also, even at 3k rpms, I wouldn't say that the 4.0 is screaming.
And the early ones were "screaming" at those RPM ranges with the national speed limits not far removed from where they are now.Which stock parameters should we go by if we are to follow them?
42rle / 29.5" /3.73 = 2052rpm @ 70mph
NV3550/29.5"/3.73 = 2320rpm @ 70mph (nearly 300rpm higher than the 42rle)
AX-15 / 29.5" /3.73 = 2349rpm @ 70mph (nearly 300rpm higher than the 42rle)
NSG370/29.5"/3.73 = 2498rpm @ 70mph (over 400rpm higher than the 42rle)
32rh / 29.5" / 3.73 = 2974rpm @ 70mph (nearly 900rpms higher than the 42rle)
Notice where Jeep put the early TJs with the autos. They were "screaming" right off the assembly line.
Is 4k screaming, or still just merely singing?I have a 2004 TJ Unlimited with 205,000 miles on it. Every time I drive it I use moderately enthusiastic throttle input and it hits 4 grand in every gear up to OD. It just doesn't care.
Not screaming at all. Just zips right on up there seemingly without effort. I will say that I believe most TJ owners baby them under some misguided notion. No owner that I have even gone on a test drive with ever drives in an even semi spirited manner. That may not mean much until you know that number is over a hundred.Is 4k screaming, or still just merely singing?
Honest opinion from someone who didn't believe the regearing hype:
Glad to hear everyone made it out safely. That's a scary sight for sure & I bet that changed his outlook on driving (if it was your son driving).Thank you for voicing your experience. When I was looking for a Jeep, I wanted the 4.0 engine. My mom had a '67 Grand Cherokee, and my son had '96 and '00 Grand Cherokees, all had the 4.0 engines. I thought they had plenty of "get up and go", but I have no idea what transmissions or gear ratios were installed.
My '05 with 4.0, 3.73, and 32" tires is a little disappointing in acceleration. I was convinced I wanted to go 4.88, but after reading about vibration issues at speed with deeper gears, I was re-thinking my choice. Now I plan to install the 4.88, and resolve any vibration issues that may arise.
This is how my son's '96 Cherokee ended its ownership (all occupants walked away uninjured)
View attachment 70924
I don't know how accurate it is or not, but I think plenty of people are afraid of the effects of a heavy foot on gas mileage. I don't know why, considering it's bad enough when you baby the Jeep. Why not at least have fun with it?Not screaming at all. Just zips right on up there seemingly without effort. I will say that I believe most TJ owners baby them under some misguided notion. No owner that I have even gone on a test drive with ever drives in a even semi spirited manner. That may not mean much until you know that number is over a hundred.
I once had a guy with a large JK Unlimited that he put a blower on show up complaining of lack of power. He drove it and babied the crap out of it lugging it. I swapped seats with him, wound it out to near redline in every gear and drifted the back end around corners with tires squealing at every opportunity. When we got back to the house, he admitted that his rig had plenty of power and I never heard another complaint about it again.
Glad to hear everyone made it out safely. That's a scary sight for sure & I bet that changed his outlook on driving (if it was your son driving).
...His reply was, "well it's only on the roof, and not a complete roll". Over a decade later, I can finally joke about the situation.