231 with JB Conversions super-short SYE issue

[LJ FlexN]

So I installed the jb conversions sssye and then the jeep sat for a week while waiting for a new driveshaft from Woods. A couple days ago when the shaft arrived I popped it in a went for a test drive to see how bad the vibrations were before adjusting pinion angle. The vibrations were not horrible but definitely needed some attention. I slid under the jeep to start adjusting controls arms and realized that everything was soaked in ATF. I wiped it all down and slid a piece of cardboard under the jeep because it was getting late, dark and I didn't feel like messing with it all that right then.
Fast forward 3 days to today. After wiping everything back off it looked as though the leak may have been coming from the VSS. I removed it and wiped it all off and reinstalled it, refilled the transfer case, adjusted pinion angle and went for another quick drive. Vibrations are gone and the leak is no longer there but now the speedometer does not work at all. It read 55mph when I was doing 65mph on my initial test drive.
2 questions; I have read on here about the jbc sssye vss leaks and failures. Could I have really went from one to the other that quick? Could I have damaged the pump in the transfer case on a 2 mile round-trip ride?

 

[GPK03X]

Most of those posts about speedometer failures suspect improper torque on the yoke.

 

[LJ FlexN]

torqued to 200lbs on install. I did recheck it today though.

 

[JMT]

So I installed the jb conversions sssye and then the jeep sat for a week while waiting for a new driveshaft from Woods. A couple days ago when the shaft arrived I popped it in a went for a test drive to see how bad the vibrations were before adjusting pinion angle. The vibrations were not horrible but definitely needed some attention. I slid under the jeep to start adjusting controls arms and realized that everything was soaked in ATF. I wiped it all down and slid a piece of cardboard under the jeep because it was getting late, dark and I didn't feel like messing with it all that right then.
Fast forward 3 days to today. After wiping everything back off it looked as though the leak may have been coming from the VSS. I removed it and wiped it all off and reinstalled it, refilled the transfer case, adjusted pinion angle and went for another quick drive. Vibrations are gone and the leak is no longer there but now the speedometer does not work at all. It read 55mph when I was doing 65mph on my initial test drive.
2 questions; I have read on here about the jbc sssye vss leaks and failures. Could I have really went from one to the other that quick? Could I have damaged the pump in the transfer case on a 2 mile round-trip ride?

Make sure the washer JB sent with the speedo is underneath the part sent by JB, and not on top. It needs to be in the right spot to register the speed. You using a speedo-healer?

 

[LJ FlexN]

I don't remember there being a washer on the install and checked earlier and there is no washer for the VSS. I am not using a speedo-healer. Other than being slightly slower than actual speed it worked fine. I am hoping that installing a set a d44s that already have ARBs and geared to 4.88 would get the mph close to where it needed to be coming from stock 3.73s

 

[tworley]

JB sensors have been known to fail, but I believe JB stepped up their QC and the issues have been resolved over the years, though thats not to say one can still fail out of the box. Pull the sensor out and with the t-case in neutral, turn the yoke until you can feel the notch on the tone wheel with your finger tip. Once you feel the notch, see if you can turn the tone wheel independently of the shaft. If you can't, then the problem is likely the sensor. The tone wheel will is clamped into place when the yoke nut is torqued so it should be able to move.

Erratic readings on the speedo are indicative of an incorrectly torqued yoke nut.

Now that you've replaced the gear driven speedo with a tone ring and hall sensor, you need a device like the blue monkey speedo healer/Dakota Digital/Jet Accuspeed to dial it in if you're changing tire sizes and/or gears.

 

[Cloaked_TJ06]

JB sensors have been known to fail, but I believe JB stepped up their QC and the issues have been resolved over the years, though thats not to say one can still fail out of the box. Pull the sensor out and with the t-case in neutral, turn the yoke until you can feel the notch on the tone wheel with your finger tip. Once you feel the notch, see if you can turn the tone wheel independently of the shaft. If you can't, then the problem is likely the sensor. The tone wheel will is clamped into place when the yoke nut is torqued so it should be able to move.

Erratic readings on the speedo are indicative of an incorrectly torqued yoke nut.

Now that you've replaced the gear driven speedo with a tone ring and hall sensor, you need a device like the blue monkey speedo healer/Dakota Digital/Jet Accuspeed to dial it in if you're changing tire sizes and/or gears.

Came across this and putting the super short sye from JB In my TJ also , what needs to be done for the speedo gear and how to program it ? New to this stuff and is it hard to get ahold of a programmer and do it ?

 

[tworley]

Came across this and putting the super short sye from JB In my TJ also , what needs to be done for the speedo gear and how to program it ? New to this stuff and is it hard to get ahold of a programmer and do it ?

I have a speedo healer by blue monkey. There are other versions available, though the brand names are escaping me. The speedo healer was real easy, just factor in the percentage the speedo is off and adjust based on that.

 

[Cloaked_TJ06]

I have a speedo healer by blue monkey. There are other versions available, though the brand names are escaping me. The speedo healer was real easy, just factor in the percentage the speedo is off and adjust based on that.

I Haven't installed anything into the jeep yet but is there more information on here about the speedo gear and programing and how to do it ? Literally didn't know this was a needed thing until a few hours ago

 

[macleanflood]

Thread 'How to calibrate your speedometer using SpeedoHealer by HealTech'

Jan 18, 2020

I saw Chris's post on correcting speedometers on a 231, using a replacement gear. However, I didn't see one covering the SpeedoHealer™. If this has been covered before, my apologies!

If not, for those looking at a Super Short SYE on their 231, or those with a Rubicon 241 case, a plug and play option to correct the speedometer is the SpeedoHealer™ by HealTech. I've installed several of these and they have all been simple to install and incredibly reliable. Previously, they were sold by BlueMonkey Motorsports, who is no longer in business. They are now available through Poly Performance...

• Irun
• Replies: 30
• Forum: TJ How-to Guides

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[lumberjacklloyd]

I used the dakota digital box on my TJ and velcro'd it behind glove box. Ran two wires to signal wire, grabbed power behind the dash, and grounded to metal structure in dash. SGI-5E, I think the current model is an SGI-100BT which has a lot of neat features.

Programming is very straight forward from there.