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Unread 01-10-2010, 12:09 PM   #16
ccbhunter14
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Heck I don't like going over 55 with my T150.

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Unread 01-10-2010, 06:35 PM   #17
-jeep-jeep-
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Mine can only go 20 kph, the speedo is broken
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Unread 01-11-2010, 02:53 PM   #18
Lawless_Jeep
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My son said I had to be doing 120 mph when I blew past the Cavalier he was driving. I think it was probably closer to 100. All I know is the Cavy couldn't keep up, and I past it like it was going in reverse.
I had my Jeep built for the interstate, so I can cruise 70-80 all day long.
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Unread 01-16-2010, 12:33 PM   #19
ThisGuyUKnow
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well I am trying to figure out if I have an issue with mine.
In 4rth I can get up to 75-80 before I feel like the engine is getting angry and when I shift to 5th I can put the gas pedal to the ground and the rig will instead of speed up or at the least maintain speed will slowly slow down to about 65 and the RPMs don't sound like they could be much higher then 1800-2000 RPMs.

I don't know the gearining in the axles. If anyone knows where the specs of the 82 Limited can be found I would appreciate it as I am pretty sure it has not be regeard. It sounds like with a t-5 and 31s I should be able to cruise a heck of alot higher. I don't want to go 100 or anything but 75-80 whould be wonderful for interstate. At 65 you get trapped behind 18 wheelers and the wind coming from them is not fun as I learned.
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Unread 01-16-2010, 12:51 PM   #20
only in a jeep cj
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You most likely have 2:72 gears and 31s are too tall for those gears to use 5th with a higher milage 258 engine. When I started to get near 200K on mine, I could not over come the extra wind resistence from the front on a semi as I TRIED to pass. 5Th never slowed me down and I had to have it for the overdrive or the RMP would be too high. On that CJ , I run 28s, 3:31 gears, T-5, and I been slowly doing a 4.6 stroker to get the power I want.
In your case, 3:54 gears would be good or a little more power from the engine would make the difference you need. Your gear ratio SHOULD be on a tag on the front axle between two cover bolts. Lower left nembers are your gears.
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1975 CJ-6 304 T15 Dana20 30/44 3.73
1983 CJ-8 258 T5 300 30/44 3.31 Looking for full or half hardtop buy or trade
1986 CJ-7 Laredo 4.6 stroker T5 300 30/44 3.31
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Unread 01-16-2010, 01:01 PM   #21
-AC-
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Ok, so I run a 304, which isn't in the scope of this post, but I got caught up in all the excitment. With 3.53's (since swapped out) and a 304 in front of a T-150, in a glass CJ-5, my motor was in the "sweet spot" at about 85 on the highway, with a LOT left. I wasn't trying to be an idiot, I just didn't realize the speedo was THAT far off, and only when my buddy who was following me in a minivan stopped for a leak and we talked did I realize I was cruising at 15 over.

Jeeps can be fast. Safe and fast? Maybe not. But certainly fast. Not usually quick...
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Unread 01-16-2010, 01:01 PM   #22
ThisGuyUKnow
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Quote:
Originally Posted by only in a jeep cj View Post
You most likely have 2:72 gears and 31s are too tall for those gears to use 5th with a higher milage 258 engine. When I started to get near 200K on mine, I could not over come the extra wind resistence from the front on a semi as I TRIED to pass. 5Th never slowed me down and I had to have it for the overdrive or the RMP would be too high. On that CJ , I run 28s, 3:31 gears, T-5, and I been slowly doing a 4.6 stroker to get the power I want.
In your case, 3:54 gears would be good or a little more power from the engine would make the difference you need. Your gear ratio SHOULD be on a tag on the front axle between two cover bolts. Lower left nembers are your gears.
My 258 has about 95k on it. I would have thought that jeep would have geared the axles to actually match the 5spd tranny that they put in standard on the vehicles. I will have to take a look at the numbers on the axle as well as go ahead and put it on jack stands and count axle rotations.
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Unread 01-16-2010, 01:05 PM   #23
ThisGuyUKnow
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Quote:
Originally Posted by -AC- View Post
Ok, so I run a 304, which isn't in the scope of this post, but I got caught up in all the excitment. With 3.53's (since swapped out) and a 304 in front of a T-150, in a glass CJ-5, my motor was in the "sweet spot" at about 85 on the highway, with a LOT left. I wasn't trying to be an idiot, I just didn't realize the speedo was THAT far off, and only when my buddy who was following me in a minivan stopped for a leak and we talked did I realize I was cruising at 15 over.

Jeeps can be fast. Safe and fast? Maybe not. But certainly fast. Not usually quick...
I'm not going by the speedo on these speeds I use my handy dandy Tom Tom. I learned that lesson in my wagoneer a while back."95 miles an hour, Officer? My speedo said 70" ok maybe exaggerating the inaccuracy a tad but still
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Unread 01-16-2010, 01:09 PM   #24
-AC-
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Yeah, I've since bought a Garmin, and that made trying to re-gear the speedo, and all of that, irrelevant. Now I take it a lot easier...

I also swapped to lockers and 3.73's, so it's not the same gig.
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Unread 01-16-2010, 03:24 PM   #25
only in a jeep cj
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[quote=ThisGuyUKnow;8701350] I would have thought that jeep would have geared the axles to actually match the 5spd tranny that they put in standard on the vehicles. QUOTE]

Well, they did. See, you have some factors against you. CJs only came with 26 to 28 inch tires in stock form. Your running 31s which add more leverage and resistance in the drivetrain, plus it makes the RMPs lower and speedometer off. Next, IF you have high gears, it was stock in the later CJs as the gas crunch was hitting hard in the early to mid 80's and this was their answer to moving the sweet spot of fuel savings up into the speed that most people were using their CJ for at the time, which was daily travel and highway speeds. It created more of a top speed and lower RPMs to save gas. Most of the 6 cyl CJs came with 3:31 or 2:72 gears while the 4cyl saw 4:10. Lastly the safe speed of the CJ back then was only about 70 to 75 with a top of 80 to 85mph....not the 100 plus that we like to push vehicles today. It was a receation vehicle that is has the areodynamics of a flat brick.

The three most important gearing factors that determine how your CJ drives is transmission gearing (low first or 4ths 1 to 1 OR 5 speed overdrive), axle gearing, and lastly tire size (as it acts like a final gear). All of these must match the rpm range that the engine is most happy with and can support. Its a big compromise. A low geared tall tires crawler will not shine on interstate travel like a stock Jeep will...and opposite is true.
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1975 CJ-6 304 T15 Dana20 30/44 3.73
1983 CJ-8 258 T5 300 30/44 3.31 Looking for full or half hardtop buy or trade
1986 CJ-7 Laredo 4.6 stroker T5 300 30/44 3.31
1986 TJ-7 Trail Jeep project in the works
2003 Inca Gold TJ Rubicon
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Unread 01-16-2010, 05:17 PM   #26
rustymudder
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this is a little off topic, but have ya'll seen the "insane inline" on jpmagazine.com. They built a Jeep straight six with 693 hp and 770lb-ft! That would make your jeeps go a hell of a lot faster!
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Unread 01-17-2010, 09:28 AM   #27
Happy Joe
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Quote:
A low geared tall tires crawler will not shine on interstate travel like a stock Jeep will...and opposite is true.
...thus the necessity for gearing to the tire size (city/highway) and going to an over drive transmission (highway/interstate) and to consider re-gearing the transfer case to 3.5 or 4:1 low range (for crawling). When properly set up the modified CJ should exceed the factory capabilities in all areas, no compromise is necessary.

I agree that excessive speed should be avoided (Jeeps are not high speed sports cars, and, unfortunately, excessive lifts are the norm). Just remember; you can go fast but how well can it stop? 33" tires seem to be close to the breakpoint for improving the brakes with the stock front disk rear drum setup, but relatively few people do a 4 wheel disk brake conversion.

Quote:
have ya'll seen the "insane inline" on jpmagazine.com. They built a Jeep straight six with 693 hp and 770lb-ft! That would make your jeeps go a hell of a lot faster!
More than about 200/250 horsepower is excessive and will enhance the (prob)ability to break parts (IMO). A good balance of; drive-ability, performance, handling, horsepower, gearing and reliability, over the widest possible range of terrain is what should be striven for (IMO). Vehicles that are unbalanced normally excel at only one thing or obstacle type, and are often terrible at others.

Enjoy!
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Unread 01-17-2010, 11:42 AM   #28
apfroggy0408
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Fastest I need to go is 65-70 and I'm fine.
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