1983 Scrambler "STUMP JUMPER". Frame off, 5.3 Conversion.

City
Willis
State
Tx
I would do some more research into flat towing a Dana 300 with the rear drive shaft hooked up, I don't want to see you damage your Scrambler :twocents:

http://www.jeepsunlimited.com/forums/showthread.php?159598-Flat-towing-with-a-Dana-300

http://www.pirate4x4.com/forum/jeep...res-why-you-shouldnt-flat-tow-dana-300-a.html

http://www.jeep-cj.com/forums/f2/dana-300-flat-tow-20930/

http://www.jeepforum.com/forum/f8/flat-towing-cj7-dana-300-lots-questions-873708/


One of the reasons why the Warn Full Float rear axle conversions were popular, unlock the rear hubs and flat tow worry free. I would disconnect the rear drive shaft, better safe then sorry :twocents: :thumbsup: :wave:

NEVER MIND, FORGOT YOU DON'T HAVE A DANA 300:crazy:
Man this news to me and bad news at that. I’m in the middle of doing a similar build to Stump Jumper with one main purpose being a flat tow vehicle for the coach. I have been flat towing Dana 300’s for years, sometimes several 100 miles at a time and never had a problem. Guess I was lucky.
 
City
Willis
State
Tx
The 4:10 gears are excellent but I think Stump Jumper could have easily taken 4:56 gears and still be great as a daily driver. I still need to change the gear ratio settings in my Computer but no doubt the fuel mileage and performance is much better.
This is surprising. I have 3.73’s that I like with my 258/T5 running 12.50x33’s. I was expecting the same gears to be about perfect with my 5.3/4L60 swap. If, like you I decide that I need lower gears I will go ahead and build my 9”rear instead of re-gearing the 20 again.
 

LetchcoreCJ7

Legacy Registered User
City
Nashville
State
TN
This is surprising. I have 3.73’s that I like with my 258/T5 running 12.50x33’s. I was expecting the same gears to be about perfect with my 5.3/4L60 swap. If, like you I decide that I need lower gears I will go ahead and build my 9”rear instead of re-gearing the 20 again.
5.3 can handle a lot more RPM before falling on its face than the 258.
 

zr10054

Car and Gun Junkie
LIFETIME
CJ-8.com Member
City
Gonzales
State
La
I’m back. Sorry but 2019 hasn’t started so well. Trying to control high blood pressure and high blood sugar. I think I got this under control now.
Stump Jumper is doing so good that I think I just take it for granted now. I do have the hydraboost brakes now but I still haven’t done anything about the spring wrap. C0C25C78-7348-42BD-A822-4C7B7E157620.jpeg
 

jerseyjeeps

Crazy about AMC Jeeps
LIFETIME
CJ-8.com Member
City
Landing
State
NJ
Goodness, SKT just called Dennis out! He flushed out JJ now on to Dennis. Oh Dennis...........
Ha..thats a good one....51 percent of the reason I flushed out was because of SKT.

Dennis - I hear you are motorhoming it to GA in March with the infamous StumpJumper!? if so I hope to meet ya there!
 

Ron84cj

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
West Bend
State
WI
This is surprising. I have 3.73’s that I like with my 258/T5 running 12.50x33’s. I was expecting the same gears to be about perfect with my 5.3/4L60 swap. If, like you I decide that I need lower gears I will go ahead and build my 9”rear instead of re-gearing the 20 again.
5th gear in a T5 I believe is .86 and the final drive in a 4L60 is .7. That is about 1800 rpm at 70 mph with 33s. That's going to bog down the motor. 4.11 gears at 70 mph is about 2000 rpm. That's ok if you are somewhere flat. And 4.56 gears would be at about 2200 rpm. That's what I'm at with my stock 5.3 in my Jeep and it cruises beautifully.
 

zr10054

Car and Gun Junkie
LIFETIME
CJ-8.com Member
City
Gonzales
State
La
5th gear in a T5 I believe is .86 and the final drive in a 4L60 is .7. That is about 1800 rpm at 70 mph with 33s. That's going to bog down the motor. 4.11 gears at 70 mph is about 2000 rpm. That's ok if you are somewhere flat. And 4.56 gears would be at about 2200 rpm. That's what I'm at with my stock 5.3 in my Jeep and it cruises beautifully.
Ha..thats a good one....51 percent of the reason I flushed out was because of SKT.

Dennis - I hear you are motorhoming it to GA in March with the infamous StumpJumper!? if so I hope to meet ya there!
Ha..thats a good one....51 percent of the reason I flushed out was because of SKT.

Dennis - I hear you are motorhoming it to GA in March with the infamous Stump Jumper!? if so I hope to meet ya there!
That's my plan. Drive the motorhome down with Mike Ragsdale and tow my 20ft enclosed trailer with Stump Jumper and some Jeep parts that Mike will try to sell. I'm looking forward to meeting a lot of my friends from the group for the first time. I'm a little bit afraid that a couple of you might just want to punch me in the mouth.
 

zr10054

Car and Gun Junkie
LIFETIME
CJ-8.com Member
City
Gonzales
State
La
5th gear in a T5 I believe is .86 and the final drive in a 4L60 is .7. That is about 1800 rpm at 70 mph with 33s. That's going to bog down the motor. 4.11 gears at 70 mph is about 2000 rpm. That's ok if you are somewhere flat. And 4.56 gears would be at about 2200 rpm. That's what I'm at with my stock 5.3 in my Jeep and it cruises beautifully.
Stump Jumper is running 4:10 gears on 31" tires. At 2000 rpms it's cruising at 65 mph and around 17-18 mpg. Remember it has a built up 5.3L making about 400 HP with a 4L60E 4 speed with overdrive bolted up to a NP241C transfer case.
 

Ron84cj

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
West Bend
State
WI
Stump Jumper is running 4:10 gears on 31" tires. At 2000 rpms it's cruising at 65 mph and around 17-18 mpg. Remember it has a built up 5.3L making about 400 HP with a 4L60E 4 speed with overdrive bolted up to a NP241C transfer case.
I was responding to Boswellcj8s post about running on 33s on his Jeep. 4.10s with 31s like yours is a nice setup.
 

designerRob

CJ-8 Member
CJ-8.com Member
City
Allen Park
State
MI
I’m back. Sorry but 2019 hasn’t started so well. Trying to control high blood pressure and high blood sugar. I think I got this under control now.
Stump Jumper is doing so good that I think I just take it for granted now. I do have the hydraboost brakes now but I still haven’t done anything about the spring wrap. View attachment 70242
I'm glad you're back and improving your health. You built such an awesome CJ you should be very proud. And thanks for all the tech in your build thread. I bet it's helped a lot of people, like me. Please stick around. We can't have too many knowledgeable Scrambler owners like yourself. :cheers:
 
City
Willis
State
Tx
I switched the rear yoke with straps to one with u-bolts today. Feeling better now.
Can you give me guidance or part number for the yoke
Spankrjs..... I was trying mine with no lift, then 3 inch of lift. With more lift it probably would have worked. Well anyway I now have a rebuilt D300 with the complete Advanced Adapters kit for mounting to a 4L60E trans for sale.
Spankrjs we live close enough to meet. I would like that.
Dennis
i have a bad feeling that I might be in your same shoes. I have a good D300 with complete Novac adapter kit already installed in 4L60. After more research I learn that the NP 241C is good to flat tow while my D300 is not. Main purpose of my build is to tow behind the Coach...
 

zr10054

Car and Gun Junkie
LIFETIME
CJ-8.com Member
City
Gonzales
State
La
Can you give me guidance or part number for the yoke

i have a bad feeling that I might be in your same shoes. I have a good D300 with complete Novac adapter kit already installed in 4L60. After more research I learn that the NP 241C is good to flat tow while my D300 is not. Main purpose of my build is to tow behind the Coach...
You are correct, just put the 241c in neutral and it’s ready to tow. Also the 241c has about 1” more offset which helps with front driveshaft clearance.
 
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