Gun Jam

Hello

I have a 66 mustang and I put a t5 in it and have some questions about its operation.

I have a t5 from a 91 mustang cobra.

I can not down shift from 2nd to first unless the car is below 5mph. I was told the t5 does have a syncroed frist and a high speed downshift from say 30mph is possible.

When I attempt to downshift it grinds badly however the trans works fine and runs smooth with no vibration or whine.

I have a 3.00:1 rearend and this issue puts me in a bad place. for example at 20mph I can not accelerate in 2nd gear and it wont let me into first effectively trapping me and forcing me to stop the car so I can get it into first so i can be on my way.

Why does it grind when I attempt to shift into first above 5mph?

-Gun

mjr46

on a t-5 or any tranny for that matter you shouldn't be shifting into first until you come to a stop or are at a roll of less than 10 mph......all 3 of my stangs have t-5's even the 66 in my sig and if I try to shift into 1st at a roll of 25 or so.. it'll grind or be hard going in for sure.. they aren't designed to be operated as such

Gun Jam

oh that sucks
there is nothing I can do to it so I can down shift into first? Mustang Steve told me his t5 could be downshifted from speed why is that?

If I had known that the t5 had an ineffective first gear syncro I might have done things differently or not at all. No after market solutions????

-Gun

mjr46

what are you trying to do by doing such??

AdderMk2

you shouldnt be trying to shift into first EVER, and its stupid of you to say "oh that sucks" this isnt your grandmothers old rock-crusher... first gear is for taking off from a dead stop, and thats it.


oh and btw, your tranny isnt out of a 91 cobra.... fyi

Gun Jam

Accelerate from 20 mph without stopping the car or ******* out.

I apparently made the mistake of assuming it would function as well as the 5speed transaxel on my 944 Porsche.

Half the reason for installing the t5 was to remove some of the flat spots from my c4 it had about a 20mph flat spot from 30 to 50 because 30 was too high for first and 2nd didnt come on strong until 50. Now i have a 40 mph flat spot because I have no first gear once the car is rolling...what type of supreme being would condone such irony, haha oh well

-Gun

mjr46

^^^^^sounds to me like you need to swap the rear end gears??? what gears are in the rear??

Gun Jam

when your right your right

3.00:1

whats a good gear that will keep rpm reasonable for highway speeds of 80 to 90mph? With my c4 I was turning about 3,600 to 3,700 at about 85 to 90mph if I remember correctly which was too high for my taste.

I know lots of people run the 3.55s with the t5 and im guessing thats probably about right.

-Gun

getafewlives

Just a note, in case you think your T5 is differen't, there's no such thing as a 91 cobra. There's a "GT cobra," which is just a GT.

Jrichber95GTS

When you do come to a stop and try to put it into first does it do just a little grind? I had the problem and it was my schyncro went out but i couldnt really shift into first until i came to a complete stop.Also another way to test our the synch is when just sitting there without pushin in the clutch try to put it in first - dont push extreamly hard just like puting it in like normal and see if it grinds that was one dead give away when i took my car to the tranny shop here