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Hi guys, this is a technical question. I did a GM powertrain conversion on my 1989 Jeep yj, won't go into details about it but need to replace speedometer gear to match the actual speed. Transfer case is a 241c with a slip joke eliminator kit, 5:38 gears and 38 inch tires, witch actually only measure 37 inches. Look at some charts and found very little information, just one that indicates that a 40 tooth output shaft gear will fit but does not mention the one that drives the cable/vss.
So, any help on the right direction will be greatly appreciated.
Thanks.
On the 241 donor, does the sender have a gear in it that meshes with the gear on the tail shaft? Or is it a stubby piece of plastic that just points at a bunch of what look like splines on the shaft?
If the sender has the gear, you can swap it out. I worked up a chart to tell you which one to use. viewtopic.php?f=11&t=11623
If it's the direct VSS on the tail shaft (i.e. no gear), I don't know if it's possible to swap out to a gear driven speedometer without swapping out the whole tail shaft.
Thanks derf, the donor 241c unit came out of a truck with 4:10 gears and 33 inch tires.
its a cable driven unit, I just got a vss speedo cable combo unit from Dakota Electronics.
So I have the twp plastic gears, one on the final drive shaft of the t case and the other one that meshes and drives the cable.
The question was, do I need to replace both gears, the one on the final drive shaft and the one that drives the cable, or just the one on the final drive?
The chart I found calls for a 40 tooth gear on the final drive shaft, but does not mention the other gear?
Your chart is better, has more choices, mine is the last one.
ScramblerCJ8 wrote:Thanks derf, the donor 241c unit came out of a truck with 4:10 gears and 33 inch tires.
its a cable driven unit, I just got a vss speedo cable combo unit from Dakota Electronics.
So I have the twp plastic gears, one on the final drive shaft of the t case and the other one that meshes and drives the cable.
The question was, do I need to replace both gears, the one on the final drive shaft and the one that drives the cable, or just the one on the final drive?
The chart I found calls for a 40 tooth gear on the final drive shaft, but does not mention the other gear?
Your chart is better, has more choices, mine is the last one.
For what it's worth, I have never seen anyone call for replacing the gear on the final drive, only the one that drives the cable. The whole idea is that one could replace that small/inexpensive gear and adjust for a lot of different combinations.
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank
Thank you guys, I had the local off road shop order me one, took almost three weeks to get it. My Jeep Wrangler has a SB 350 TBI and a 700R4 tranny.
The ECM needs to see VSS signal or the check engine light will come on, and the stock speedometer needs a cable to operate. With the 40 tooth gear it will read close enough to real and the cable won't wine.
I'll let you guys know once I get it install and road tested.
Ok, got the speedo gear swap and road tested. No more whine from the cable but speedometer still reads almost double the actual speed, a clue why the odometer reads over 250k.Found a NOS speedometer on ebay for 160 bucks, offered 100 and offer accepted.
Installed and road tested, just 1 mph off from my gps.
I'm satisfied and considered it fixed.
Thanks again.