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NP231 SYE Yoke Upgrade

348 views 7 replies 4 participants last post by  Got it at last  
#1 · (Edited)
Hi y'all,

I have installed a Teraflex NP231 Extreme Short Shaft Kit (PN 4444400) onto my transfer case. However, the yoke that comes with the kit (PN 600071 I believe) is a 1310.

I have a hellcat in this jeep now and I need to upgrade to a beefier 1350 because the 1310 broke on the dyno at 599lb-ft.

Some research has lead me to PN 300485

Any ideas about whether this will fit my SYE kit? It's 32 spline, which matches my existing yoke. Also, it looks like there's a matching seal PN 300473.

I've talked to TeraFlex and Advanced Adapters. Neither of them could offer any help, unfortunately. A local driveline shop couldn't find a matching yoke, either.

Any suggestions appreciated.
 
#2 ·
Have you tried Adams or Tom Woods driveshafts to see what they say?

Being driveshaft makers I would think they would have an answer since they would be your go to folks for a new shaft with the 1350 u-joint.
 
#3 ·
Maybe this one.

 
#6 · (Edited)
Called Tom Wood's driveshafts today and he told me that the Super Short SYE kit specifically doesn't work because of the extra step required on the yoke. Said I'll likely have to purchase a yoke and have a machine shop cut that step into it. Also said they wouldn't be willing to do that. Argggg
 
#4 ·
The yoke they sell with the short kit. Is it the same as the regular kit, part number?
Unless its custom and would think it is not should be a 1350 that fits. wont cost that much to buy the one you think works and measure it or eye ball it better.

I have broke rear 1310 with only a 3.6 on 37s. Happened two times on hard bump and goes up steep falls. First time i was able repair. second time twisted the shaft a bit so tossed it and went 1350 flange both ends so no caps.

The tcase is not even rated close to that much torque. Off road on hard when you need to bump it, harder on it then a dyno run. way more load variables than rolling over on pins. I guess the jeep is on 60s at least?

issue with top speeds on a jeep will be tires and at a point vibes with driveshafts mainly front if a DC type. Tires unless street tires. Mts tend to top out at 100mph or less( especially say 35s+). Ats most not much better. Thread you posted in a guy had vibes at 120. LOL........ i bet. You want Hubs up front, floating type axle. so only the tires are rolling.

Last time i built for speed was very long time ago. before some were born. I had a jeep then too. But to go fast you need a bit more stability. have a old z28 early second gen with XCH454 and six speed manual. 5+ a .87 OD. Back in 1980 I had a Doug Nash 5 speed few had those. In those days it was rather hard to catch. with a 44 gallon fuel cell. Top speed was limited by air flow really. Those cars are a brick at those speeds, look sleek but push air more then glide through it but it was the 70s and 80s speed limit was 55mph. I was like Sammy. Right me up for 125< not even in 5th yet. I was pulled over by the CHP in Cal doing nearly 3 time the posted about 175. 5th gear 6500 rpm thing would run at 6k not an issue. said he heard me from miles away in the dark going through barstow 2 am. He let me go said he never seen a car moving like that. I seen him getting on free way he was standing in the only open gas station and was down shifting hard to stop right where was getting on. I shut it off before he got out. first thing he said was of course, you know how fast you were going? I said no the speedo tops out at 150mph. He smiled and said start it up. He loved the car i think said he thought he stopped the Bandit car was Black back then, but its a camaro not a firebird?. He asked where you going at 150+. said vegas. He said slow it down a bit..... Was what some would call a star light run. Socal to vegas and back leave at sun down be back by sun rise. You have to gamble too. we still made it had to make sometime but it was a runner for sure. especially with all that fuel...was filling it up and a older guy then was looking at the pump. 35 gallons went by, he looks at the car and gets looks under the back to see where its all going... clicked at 40 gallons. Road better with full tank. think it off set the weight of that BB. Could feel it when it was empty, rear gets looser.

Cars in red today and it is retired. sits in a garage. Life in slow lane
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