Tremec T56 - difficulty getting into reverse

GlynMeek · #1 (**permalink**) 10-29-2007, 10:39 PM

I have a new T56 gearbox with only a couple of hundred miles on it. It works well, but I have a problem getting it into reverse when the engine is running (seems fine when the engine is off). No crunching or grinding when it does go in, it just seems somewhat reticent (!!!) to engage.

All the forward gears are fine, changing up and/or down, and I was wondering if the clutch might need just a minor adjustment as it might not be releasing 100% completely when I press the pedal.

Any suggestions?

Glyn

Excaliber · #2 (**permalink**) 10-29-2007, 11:49 PM

The T56 uses a 'synchro' type of shifter block like the rest of the gears use. If the other gears shift OK, then reverse should shift OK, ruling out clutch release. More likely something is wrong with the shift mechanism for reverse itself. 5th, 6th and reverse are all housed in the tail shaft area. This is a pic of reverse gear.

Badger · #3 (**permalink**) 10-30-2007, 02:20 AM

You are not alone...This seems to be a common problem with T56s. Badger.

Roscoe · #4 (**permalink**) 10-30-2007, 07:42 AM

On my 3550 I sometimes have some grinding going into reverse. If I go into 3rd first I get little or no grinding going into reverse.

Roscoe

Aussie Mike · #5 (**permalink**) 10-30-2007, 08:15 AM

The T56 has carbon synchro rings for all the forward gears but reverse is a brass synchro ring for some reason. I have often heard of them having troubles getting into reverse.

A few of the used T56 boxes I've stripped and built have had quite worn teeth (maybe dogs is the right term) on the section that engages with the synchro hub. Fortunately reverse gear has these teeth on both sides of the gear and only one side is used. You can pull reverse gear out and flip it over and use the fresh set of dogs. To do this you only need to strip off the extension housing.

Cheers

Roush #1 · #6 (**permalink**) 10-30-2007, 08:55 AM

Glyn,

I think the T56 has a reverse lock out solenoid that should be activated making the reverse shift much easier.

Overiding this solenoid manually would make the reverse shift very difficult.

Jody

GlynMeek · #7 (**permalink**) 10-30-2007, 09:21 AM

Thanks everyone. I read Jody's post and realize I have NOTHING wired to the reverse lock-out solenoid to activate it. My suspicions are that this is indeed the problem. I will research and let everyone know.

Perhaps THIS is why folks have reverse problems with the T56...the manual with it SUCKS as there is nothing I can find about 'wiring' the damn thing!!!!!!!!!!!!!!!

Glyn

Roush #1 · #8 (**permalink**) 10-30-2007, 10:10 AM

Glyn...

I feel the same way you do and even have a sore shoulder.
I have 1400 miles on my T56.

The only infomation I have found is here:
http://drivetrain.com/gmt56inst.html

Good luck!

Jody

Excaliber · #9 (**permalink**) 10-30-2007, 10:34 AM

Sure sounds like the solenoid lockout all right.

rsb427 · #10 (**permalink**) 10-30-2007, 10:58 AM

years ago late 80,s I think i was looking at a mustang gt, upon test drive I found car to not shift into reverse without diviculty.after making a comment about it the salesman told me that he had seen a bullitin on this and said you should put in 1st gear clutch in,then reverse when backing.well guess what it works and on other cars as well no clunk or grinding. I have a tko600 in my car and it works on it as well I dont know if this helps center something or what but it seems to work try it! good luck. sorry I have to go,but the suns out and the big block is calling my name!

Excaliber · #11 (**permalink**) 10-30-2007, 11:18 AM

Thats a good tip for trans like Top Loaders, T5's and others that have 'square cut teeth' with no synchro for reverse. 1st gear on a T5 has a synchro, engaging it first is easy, and it stops the trans gears from turning, thus making the shift into reverse easier.

The T56 all ready has a synchro on reverse, shifting into 1st may help, but it shouldn't make a lot of difference either way on this trans.

wtm442 · #12 (**permalink**) 10-30-2007, 11:20 AM

I have a Tremec 3550 just like Roscoe mentioned above. Any time I try to shift into reverse, it "may" grind a little. But if I shift into first gear, and then shift into reverse, its as smooth as butter on a babies a$$.

Excaliber · #13 (**permalink**) 10-30-2007, 11:31 AM

Tremec 3550, square cut teeth on reverse, non synchro.

Jimi G · #14 (**permalink**) 10-30-2007, 02:00 PM

If you can get it into gear with the engine off it is a clutch related problem. Something might need to be adjusted alittle more but it is not the T56. jimig@standardtransmission.com

GreenSnakeDoc · #15 (**permalink**) 11-02-2007, 07:21 AM

When I want to shift into reverse after starting the engine with my T56 in my C5, I always shift into 5th first while holding the clutch in. Then it goes right into reverse without grinding. With the engine shut off, I can not shift into reverse. I think this is normal with T56s.