7290 u joints

[vitamin c]

What's the better Spicer 7290 joint, the solid 5-811X or the greaseable 5-1309Y? I don't think either are solid.

 

[R413]

I use greasable and have never broke one with burnouts and racing with slicks.

Seems to me it's good to get some grease inside periodically.

 

[Bird 426]

I have twisted a greasable u-joint to destruction. I would say that there are trillons of them out there and no problems. Your personal choice.

 

[Vitamin_A12]

We solely use the non greaseable 5-811X. They are not cross drilled and have a superior sealing system.

 

[vitamin c]

Thanks for the replies. I ordered the 5-811x's and Mancini sent me one of each, so one of them is going back.

 

[gkent]

You realize there is a right way and wrong way to install a greasable u-joint - right ???

You want the grease fitting in "compression" not "tension".

 

[beanhead]

Anything with some oates, non-greasable is preferred. The off-roader crowd likes the greasable ones because they can flush out the gunk and water but for the street muscle guys, that 5-811X is the common choice.

 

[RemCharger]

You realize there is a right way and wrong way to install a greasable u-joint - right ???

You want the grease fitting in "compression" not "tension".

Can you elaborate

 

[70ChargerRT]

Just blowed one out. It was the 1st greasable u joint I ever ran. Had 2k miles on it. Junked the driveshaft also. getting a new driveshaft built right now with a 1350 and swapping out the 10 spline 7290 yoke for a 1350 and going back to a non-greasable spicer

 

[R413]

What happened to the yoke? It is spread apart where the u bolt goes through.
If yoke doesn't support the u-joint then any u-joint will fail.

 

[70ChargerRT]

What happened to the yoke? It is spread apart where the u bolt goes through.
If yoke doesn't support the u-joint then any u-joint will fail.

lol. what? thats what happened to it after it failed lol

 

[gkent]

See below. Under power the driveshaft is "compressing" the grease port - which is the weak point. This is acceptable. However if installed such that the the grease port is in "tension", the chances of breakage a significantly higher - virtually guaranteed with a combination of power and traction !!

 

[R413]

Where the the grease fitting is it either getting pulled apart, bad, or pushed together, good.

 

[RemCharger]

See below. Under power the driveshaft is "compressing" the grease port - which is the weak point. This is acceptable. However if installed such that the the grease port is in "tension", the chances of breakage a significantly higher - virtually guaranteed with a combination of power and traction !!

View attachment 1973612

Thanks. Pretty clean diagram too. Makes sense.

 

[AZMoparJoe]

Agreed on the proper orientation of the zerk fitting. ALWAYS on the compression side of the joint. I went bottom 10s with a brake for years with greaseable Spicer joints. Never a problem.