Driving thru gears ( hard load/upper rpms ) 1st thru 4th gears shift fine , when

I shift into 5th nothing when I let out the clutch ,then when I try to find it the

shifter feels slightly jammed put it back in neutral then back in 5th and it feels

like it went into 3rd (rpm spike) try again and I get neutral , I try 4th and no

problem, I try 3rd no problem, I try 5th again and I get nothing . So I pull over

and try again ,this time I take it easy shifting and no problem I get all 5 gears .

I checked the bushings and the linkage they fine, BTW this is a TAILshifter

thanks Bill D.

How 'bout your tranny or motor mounts moving around under load?

Their almost new 911 solid rubber all 4 , This tranny has fairly new
refresh with a shorter 3rd & longer 5th

thanks Bill D.

Shift linkage sliding on its splines?

I would suggest that the fifth dog teeth and the fifth side of the fourth fifth slider is worn. Try holding it in gear for awhile and see if it again starts to work

I hate to be the bearer of bad news, but there are a few things that make me worry about the worst.

1- these symptoms match very closely what you would see if the retaining nut on the input shaft were to come loose. I just fixed this on a race box yesterday.

2- You just had the box gone through - this supports the possibility of #1.

This is only IF all externals are perfect.

Thanks Gentelmen ,I guess I need to go thru all EXTERNALS first

I might have jumped ahead on this , I just got done reinstalling the
motor & trans after being out a year .

Doc what are the odds of the nut coming loose , I purchased this trans
in april 08 it has maybe 1000-1500 miles on it

thanks Bill D.

I dont know who rebuilt it, that changes the odds considerably. The race box I just fixed was a "recent rebuild" as well. The guy had no clue. He rebuilt the 3.0 /6 is was mated to, also. That needed some serious love to be whole again. If it was rebuilt poorly, then you would likely see a failure at about that mileage. Sometimes things just fail, also. Odds are less of that happening, but not impossible.

I had a shift console so worn out it was riding up out of the shift rod fork. or both pieces were worn out it sure sucks.