Technical IMPROVING THE SHIFTING ON A T5

IMPROVING THE SHIFTING ON A T5 [or T56]

A joint effort "Tech" thread between myself and my husband [ Kerrynzl ]

This is not another DIY "Short Throw Shifter" thread [There are plenty of threads out there on how to do a DIY short throw shifter for a T5]

For this we'll be modifying a T56 shifter on our race car as an example ,but a GM T5 shifter is a straight bolt in swap with a T56

These modifications will also apply to Ford / GM / Dodge T56's and T5's with a stamped sheet-metal shifter base.

Using 0.6 seconds as a base mark for shifting, a 33% reduction in throw would theoretically save 0.2 seconds [or 0.6 seconds with 3 shifts in a drag race which is a good gain]

On a road-race track the same 0.2 seconds gained at a corner exit [50 mph] is about 7'' of distance providing there was a 4% loss in velocity during the shift.

Because road racing is not "side by side" racing ,there are plenty of other techniques to again an advantage [some are unsporting]

A missed shift is more problematic and the time wasted recovering from a missed shift is detrimental to the end result



If you want to DIY a "Short Throw Shifter" click on the link below [or better still search the H.A.M.B] these mods can also be done simultaneously

https://www.stovebolt.com/techtips/shifter/index.html

If you have a Camaro T5 or a Viper / Cobra T56 you could bolt on a shifter from an S10 T5 . GM used a taller tower to offset the throw from a longer gear lever.




This thread is about improving the precision and driver feedback of a T5 / T56 shifter [especially the dreaded 2nd -3rd cross shift]



@Budget36 @Nostrebor

 

Now this is the "hard truth" most of shifting problems aren't actual shifter problems, but driver technique . As Kerry said "They couldn't drive a nail into sand"

Better driver feedback would definately help.

With a 4 speed "H" pattern a driver can be brutal when cross shifting from 2nd to 3rd without much in the way of consequences.

But with a T5 / T56 there is a "Double H" pattern ,so it can easily select 5th instead of 3rd [ shifting from 4th into 5th on a T56 can sometimes select Reverse if there is a weak reverse lockout ]

The normal driving technique for a T5 is to hold the lever to the left and pull it back from 1st into 2nd. Then with an open palm and thumb slightly down push the lever forward from 2nd and the centering springs cross shift it into 3rd. "You do not push the lever over to the right but straight forward."

Now T5's and T56's do NOT have any internal springs to centre the shifter to the 3 - 4 gate. [except C5 Corvette]

The 3 - 4 gate relies only on the shifter to return it

If you pull a shifter off a transmission you can wiggle the offset lever L & R with no resistance [using a finger]

This is where the aftermarket manufacturers have filled a void.

Attached is 3 photos of an aftermarket shifter dismantled [showing the centering springs]
[stolen off the internet]

 

One of the problems with "short throw" shifters is when the length of the ball stub is increased in relation to the cross bar the leverage makes the return to centre resistance softer.

In theory the cross bar should be widened proportionally but that then requires longer travel return springs

So what the aftermarket did was add stiffer springs to restore the resistance.

Similar to Valve Springs at high RPM , when you shift faster a stiffer spring is needed.

Stiffer springs are usually shorter with thicker wire , and some are also shimmed to get a higher seat pressure [which isn't a stiffer spring]

These springs will eventually break or coil bind and break the cross- bar





With Road Racing the driver is constantly on the shift lever [ Bruce McLaren Motorsport Park here in NZ needs 26 up and downshifts every lap with a close ratio 5 speed]

Every aftermarket shifter we're tried over the last 2 decades has eventually failed [the worst didn't last 1 meeting] Most racers accept this as a throwaway part...... and a cost of racing

We looked at stock production race cars many years ago [they never had the same failures] So we switched back and did the following mods and never had a failure since.

 

@Mimilan

Hey Mimi, make sure to mention me again tomorrow when you add to this!

Kerry wasn't kidding when he said he'd ask you to put this together

 

take a SsangYong musso, or rexton 2001 t5 -
remote shift

 

Thanks @Mimilan for taking the time to follow up on our request. I am looking forward to future installments!

 

They also do a remote single rail for the Musso. [ We looked at adapting this set up to an early T56 to get the shifter rearward ]



Edit: The bolt pattern on the linkage cover is 2.88" W x 3.44" L which is identical to a Ford SVT / Dodge Viper T56 shifter bolt pattern.

 

I'll see your remote and rasie you a
rover v8 or 216 buick bell housing from a tvr with the mustang box
funky forward shift from a tvr

 

My 63 Belair 2 door post car has a T-5 out of a 91 IROC shits like butter. Nothing could improve the way it shifts.

 

They all do....There is nothing wrong with the transmission [just the shifter]
Does your trans have an Aftermarket shifter or stock shifter?

Most aftermarket shifters usually fail 2-3 owners down the "food chain" [Just when the latest "trick" shifter renders the old shifter obsolete]

In a drag race there is usually 3 aggressive upshifts per race.

A 10 lap road race can have up to 260 aggressive gear changes [3 races a meeting = 780 gear changes]
If you did 8 meetings per year that equals 6240 aggressive gear changes.

An aftermarket shifter will eventually break. Factory shifters don't.

@Budget36

 

Mimilan, My T-5 has the stock IROC shifter. As you know they were never made for drag racing and speed shifting as there are no shifter stops installed. That can be also be modified if required. FYI this 355/ T-5 combo has been in the car for 10 years now with no problems. I couldn't be more satisfied.

 

They are great transmissions when in good condition. And the owners really need to be honest about how they will use them.
This thread endorses Factory OEM shifters but changing intended usage requires some simple modifications.

Last Century Kerry modded a T5 and put internal stops in the transmission [T56's already have them]
This involved a floating collar on the shift rail in front of the offset lever [Camaros were .200" thick] and block of aluminium behind the offset lever that was externally screwed in place.

Stops are only needed for drivers who whack the lever like a hammer [poor skills]. The stops are always set up on aftermarket shifters with the bolts backed off 180 deg for clearance.

They are not needed

 

[back to the thread]

The example we'll be using this thread is an O/T T56 [but everything applies to T5's]

This example was slightly different because it had a remote shifter adapted [by Ford] so the racing transmission has the lever in the correct position without cutting the tunnel. The transmission was a Tremec special order T56R for Ford Racing, [externally it is similar to other production T56's]

Note: Some of you H.A.M.Bers out there could also use your imagination to forward mount a shifter using this method [S10 tail-housings are getting rare]

This was good enough to be a factory fitted method

The shifter:




There is only 3/4" [19mm] clearance above the shifter ,so this made us remove the transmission [for the H.A.M.Bs viewing benefit] .
In normal situations all you need to do is pull the shifter.

The shifter on the transmission is just a standard unit with a "T" pivot welded to the lever
The whole application here:


Please note: One of the advantages of the Factory Remote ^^^ , is they altered the ball to pivot height on the remote lever to shorten the forward and aft throw.

The Left and Right movement is unchanged . 25 degrees movement at the shifter equals 25 degrees at the lever.

@nobby [This is how Americans do it]

 

You now need an extra/ spare shifter to cannibalize the diaphragm springs from.
The diaphragm springs are used by the factory for reliability, They don't break. and They can not "Coil Bind"

These are plentiful at swap meets etc [most people throw them away when they fit aftermarket shifters] We've been given them before, and have paid as little as $5 for them at swap meets.

Because of self isolation during our present Coronavirus crisis ,we had to pay NZD $50 [USD $35] online for the one we will use [including shipping]

We ended up with a Ford / Holden T5 shifter. A friend is swapping a Holden T5 Tail housing onto a Camaro T5 Transmission so we swapped our shifter for his ,saving us both some grief.

Now: There are 2 types of shifters of the same basic design

One has a Steel Ball and the other has a Delrin plastic ball

The steel ball here


And the Delrin ball here




The Delrin ball shifter is more desirable [we'll explain later] ,so if you have a steel ball shifter [as in our case] Now is the time to change over to the delrin ball type[ if you have one as a spare shifter]

Luckily for us, we ended up with a Delrin ball shifter when we did the swap [so did our friend , but both of us ended up getting the correct shifter base bolt patterns]

The first part involves cutting off the rear folded over tab on both shifters


Here it is now cut off so it can slide out ready to be disassembled .Some people prefer to unfold the tab, But we're never had much success doing this, because it usually cracks requiring welding later

 

We've taken the top off the original shifter ,removed the diaphragm springs and reassembled it to check the clearances. This is a steel ball type shifter!

If you look closely the nylon /plastic bushing is below the level of the 2 adjacent diaphragm spring stops. A shifter in this condition will always be loose forward and aft and rock slightly side to side.


This is the original shift lever stub with the steel ball [the 3 diaphragm springs have been removed] The nylon /plastic bushing is seen at the top. This prevents the cross bar from wearing through the diaphragm springs


This is the reason we don't recommend the steel ball type shifter , It sits inside a rubberised plastic "Cup" designed to isolate vibrations.


These eventually sink down causing the issue shown in the top photo

 

In the shifter base underneath the rubberised plastic "Cup" there is a nylon shim that also breaks.


This shows the shifter base with the shift cup removed but showing the nylon shim. It has excessive wear where the cross bar is located

This is caused by compliance in the shift cup [and over enthusiasm by the driver]



This is a close-up of the excessive wear in the shifter base [it is not worth saving]

 

This is the Camaro T5 shifter assembly

It consists of the shifter stub, Delrin ball, bushing "ring", 3 x diaphragm springs and the top stamped cover.



If you look closely at the diaphragm springs, you can see some little "tangs" on the ends. Some springs have these and some don't.

You can mix and match both types of springs with one caveat: If any of your springs have these tangs ,You must use the appropriate top stamped cover [which is slightly larger lengthways]



The next 2 photos are of the shifter base with an integral steel "cup" [this is in Good condition and will be used by us]




The next photo is not ours [It is plagiarised from the internet, but worthy of posting here]
It shows both types of shifters side by side

The shifter on the left is a Ford / Holden bplt pattern , on the right is a Camaro ,S10 ,Viper ,SVT Cobra bolt pattern.

The L/H is a steel ball with a rubber cup, and the R/H is Delrin ball with a steel cup.
The L/H diaphragm springs have the tangs on them, and the R/H diaphragm springs are oval shaped.
The L/H stamped steel cover is slightly larger than the R/H stamped steel cover. [you can just see the difference in the outer lip]


If you were to mix and match the diaphragm springs you must use the L/H stamped steel cover. [or grind off the end tangs]



You cannot mix a steel ball with a steel cup base plate [which would seem to be a perfect solution on race-cars] We've already tried that.

The steel ball is made slightly smaller to allow for the nylon shim underneath and also the extra wall thickness of the rubberized plastic "Cup". [combining this with the steel cup creates too much clearance]

 

Very informative. Even though my roadster still uses a 1932 Ford transmission, I read the whole sequence, and it was important to me that someone took the time and effort to help others from making what could be expensive mistakes.

 

Thanks ! It was an education to me , as I write this up for Kerry. That's why I try and post in "plain English" [some of our terminology may be different in NZ]

More to come!

 

Most Factory shifters have 3 Diaphragm springs . One is thinner than the other two [you can easily feel the difference]

Every shifter we're dismantled had the thinner spring at the bottom .This seats against the nylon bush that separates the steel cross bar from the spring

Now we experiment with different spring stacks [this is stacked to your preference]

On street cars we recommend one thin and three thicker diaphragm springs. [4 springs]
On race cars we recommend one thin and four thicker diaphragm springs. [5 springs]
If you have a bench seat application with long shift lever ,we recommend the race car set up.

Because my shift lever has been modified, We used the existing Camaro shift lever just to test it on the transmission.[it was temporarily clamped together with vice-grips]

With 5 diaphragm springs no matter how hard we tried to miss-shift from 2nd , it always cross shifted into 3rd. [ 1-2 shifts and 2-1 shifts required side pressure against the lever]


Another variation with some shifter bases is shown here. If you use the "open" variation [lower] it is highly recommended to use a shifter "dust boot" to prevent debris finding it's way past the shifter.

underneath the base


Top view


A cheap reliable alternative to the Factory dust boot is a CV boot from a 1991-98 A101 Toyota or a Honda Prelude [these slip snugly over the shifter top cover]

 

The next process is only needed for our shifter .

After we were satisfied with the results of the shifter using the Camaro shift lever , It was removed and dismantled again.
This is so we can swap back in the shortened shifter stub/lever that is only applicable to our race car.

This is the shifter stub assembly with the 5 diaphragm springs [Please note: It had the wrong steel ball for the photo, we swapped it for the correct Delrin ball but never photographed it ]


This next is required to finish all shifter mods.

After the shifter is assembled it is fuse welded together at the rear with a TIG welder.




Here is our shifter installed. We had to use an OEM dust cover because of the shortened shifter lever [normally the CV boot is a lot better]


Apart from short throw mods, these modifications would perform as good [or better] than any aftermarket shifter. And it's life expectancy is certainly a lot better

And it will save you a couple of hundred $$$

I hope this thread helps out
Stay Safe Everybody

@Budget36 @Nostrebor

 

Just the CV boot tip made this worth the visit. The rest is even better! Thank you for taking the time to share this with us regular blokes.

I have a pile of shifters to cannibalize... added to the list!

 

X2 for sure, heck of a write up/how to!

Thanks again!

 

thanks for the write up it the working now for my rat rod

 

This is a great thread and added to my knowledge of these shifters! Thanks!

 

Subscribed!

 

Start a thread for your build, we'd all like to see the comments.

 

I’ve had my shifter assembly apart (just today!) and back together. Something does not seem right. Shifter feels super loose. ** My shifter has the 3 Teflon plates in it, and one of the pics above makes me wonder if I put them in upside down. Does the peak of the arch point up or down, when installed correctly?

the pic above where the assembly is zip-tied together shows them pointing down. I installed mine pointing up (because I can’t remember how something came apart, for longer than 5 minutes.).

please advise. Thanks!

 

Thanks for the thread! Now I know what shifter to look for...I'll be following.

 

Downwards across the centre,[ or "U" shaped ] so it has spring loaded weight bearing down on the cross bar of the shifter stub.

This is the correct orientation here.
The red circled area shows where the cross bar nylon bushing has been rubbing against it.