Superior Trans Parts TF-TC Kit

[BudW]

‘78 was the mid year change over from non-lock up to lock-up.
About 6 months of big blocks got lockup transmissions, before the big blocks went bye bye.

Changing differential gear ratio will have no effect on lock-up - except it will come on at a different MPH (based off of the difference in gear ratio you are currently using). Lockup comes on when coasting or low power, so gear ratio and tire size will not effect lockup operation.
Also the shift points will be different with tire size/gear ratio changes as well - but to transmission, it is acting the same as it always did (transmission doesn’t see tire size or gear ratio). It only hums along at a higher (or lower) engine speed based off of what MPH you are driving.

Installing any kind of shift improvement kit on a worn transmission generally causes more problems than fixing. If you have transmission problems, get that fixed first.

A automatic transmission is a hydraulic computer. There are several kinds if shift improvement kits out there, each one is programming the transmission in a different fashion. Some are good improvements and some are not so. The factory worked hard to make transmissions last past warrantee, for smooth shifts (and better fuel economy?) and seldom for performance.

There is several tug-of-wars going on inside and most shift kits alter such by one or two methods. Increasing line pressure is one method. Changing governor weights/springs, is another method. As well as changing clutch pack springs, changing accumulator springs, and so forth. Changing any one item can/will effect the operation of the other items. The worst thing you can do is make two opposing clutches engaged at same time (think applying gas and brake at same time) or having a clutch apply late (like holding clutch petal down and gas petal down after shifting to next higher gear).
Listen to your transmission shop. He has to stand behind his work and he will know what is good (or bad) for your transmission.

The good thing about todays electronic transmissions is they are easier to program (and not so messy).

I can tell you exactly what a 904, 998, 999, 727, 518, 500, 604, etc. transmissions are doing at pretty much any time, and have been inside many hundreds of them.

Note: the automatic shift kit I prefer to use . . . is manual transmission.

 

[Bruceynz]

Thanks Bud, ok so I really have nothing to be concerned about changing from a 2.2 to a 3.21, the speed when the lock up comes in will be 46% lower (the % diff between 2.2 and 3.21) but won't effect anything?

Bud - Just out of interest would you have just the spring to move the lockup higher or can you recommend a spring? I think that's all I may need to change is the lockup spring in the valve body? Just to try and shift the lockup a bit higher up again like it was with the 2.2

In the pic is that the lockup spring if I could get a stiffer one would up the lock up speed?

 

[BudW]

There has been a few changes to lock-up engagement over the years – so I’m hesitant to reply – for I don’t want to give incorrect information.

I know some people want to get rid (or disable) Torque Converter Clutch (TCC) lockup, which is also fine in my book (as long as the person knows the consequences).

For those who do not know, a "non-lockup" torque converter will have best efficiency is about 90% (10% slippage), when cruising at highway speeds, or whatever speed you have settled to.
When power is applied, the efficiency drops drastically, but torque multiplication jumps up just as dramatically (which is what you want when you apply the gas).

In mid 1978 Chrysler went to a TCC or lock up torque converter in order to get better gas mileage. That 10% slippage is equal to 10% gas mileage savings, so torque converter efficiency is now at 100% (good news for fuel mileage). The system remains basically the same today, but the internal workings has changed several times (and therefore method of how it operates). The first three or four years were more troublesome as bugs got worked out.

The system is designed to un-lock when power is applied and re-lock when cruising or light throttle – so therefore it “shouldn’t affect performance at all.


In my opinion – if it is working, I wouldn’t mess with it. If it was easy to access (not having to be under car with hot fluid dripping/pouring in your face), then I would say tweak away – but working on those to make a minor modification to a working non-critical system, is a royal PITB.

Now if it is a normal shift point (non TCC lockup) issue or if system is not working, then my opinion changes completely.


If you don’t care about fuel mileage, and if one was considering disabling the system – I would have a different opinion to give.


In my world, I have an F body and an M body that I want to convert to big blocks. The M body first – and not sure what going to happen to the F (yet), but there are two engines (actually closer to a dozen engines) are already in my garage, and a handful of big block 727’s. I don’t like driving automatics (give me a stick any day) but going to put a 727 in the 5th Ave so my wife won’t complain about driving it.

On my 727 build, I’m planning on converting it to TCC lockup, for the plan is to drive the car and the 10% fuel mileage will help offset the cost of feeding the beast. That and along with the outside air system and several other fuel mileage considerations.

BudW

 

[Bruceynz]

Hi Bud,

So the car will end up going 1st 2nd 3rd and instant lock up, is that an ok for the trans to work? It will all happen very low speeds, will this casue lock up shudder at all? If I took the spring out, and I know this is probably crazy talk but measured it, then stretched it says 1/2" and put it back in would that change the lock up? (very crazy engineering idea I know)

Thanks
Bruce

 

[BudW]

Can you get me the numbers stamped on side of transmission, please?
My brain is a little fuzzy on what year transmission you are working with.

My ’86 999 (or 998) transmission has a short bit of delay once it goes into lockup, shortly after 3rd gear shift occurs – maybe a second or less – under normal driving. That is not hurting me or transmission a bit.

Now if is doing this under moderate to heavy acceleration, then I would be concerned.

 

[Bruceynz]

Hi Bud,

Its 998 trans, 1983, 4 clutch pack, lock up. The 999 was the 5 pack one used behind 360, yes this is the problem, it can lock up and full power can go through the converter, well thats what I was told some time ago when i was going to do a diff change on a 1979 Chrysler New Yorker but I sold that car never did the diff change and a some years later have got back into it. I was told if I change the ratio with out sorting the lock up I will burn the lock up out very quickly as full power can go through the LU clutch and it can't hold it.

Your thoughts as I am not a trans guy, but have a little knowledge.

Thanks
Bruce

 

[Bruceynz]

Hi Bud,


Because the LU is all hydraulic and the box just whacks in the LU which appears to be a certain RPM (which looks like 1200) when in 3rd gear and the wesay smogger engines that were in front of the lockup had less power than a snails fart to damage the LU clutch. So lets say it goes 1st, 2nd 3rd so 35mph your in top and you are picking up speed then you hit 42mph and lock up. That’s all pretty easy and good and probably suit 95% of most peoples driving, lets face it no matter how much of a hot rodder you are we all are not all doing flat out take offs on the free way, we in general ease up to speed so the LU is never going to get loaded up hard. I change the diff ratio now and put a mild 360 in front of it, I now have the LU coming in at 28mph, in first gear probably!!! And I have 260hp going through the lock up. Soon as that LU slips we get a burnt out LU clutch. As I said I not an expert trans guy, but that’s how I suspect it goes. My father had an old Toyota and it had an electric lock up clutch, it only came in when the car was under light throttle. Anyway you may be able to look at the fluid diagrams, (they do my head in) and see how the lock up actually works and in fact If it does work how I think, you know it wouldn't be the first time I have made a mistake. If the LU was done when the line pressure or what ever it is called balanced out when it was in top gear then locked up the LU would be continuously variable but I suspect that's not the case.

I wanna get my lock up spring, pull it out, stretch it half an inch and put it back in


Thanks
Bruce

 

[Bruceynz]

What bout if I shim the spring with a washer, that may help? Any ideas if that is good or bad?

 

[80mirada]

Throttle position will affect the lock-up engagement. The lock-up and shift points vary thanks to the kick down valve position. Make sure to check the kick down linkage adjustment.

 

[Bruceynz]

Have kick down adjusted so hard back at full throttle, spent some time sorting that out, thats how you adjust it correctly?

 

[80mirada]

Yep, make sure it goes all the way forward when the throttle is closed, a small spring hooks to the linkage and the throttle stud. Or there can be one from the front of the linkage to the throttle spring bracket

 

[Bruceynz]

This LU is seems to becoming to hard for a 10% saving, if I cook the clutch I dunno what happens, probably get burnt stuff in the trans fluid, I might just pull the spring out, measure the depth of the hole, cut a piece of alloy rod and put it in there so the dam thing can never lock up, problem solved Will this cause any issues?

 

[80mirada]

I doubt you will have any problems. The kick down will help regulate lockup to light throttle. Mine crapped out thanks to my kickdown linkage not working correctly.

 

[BudW]

Bruce,
You sound smarter about transmissions than a bunch of people I work with.
At home, I only have three applicable service manuals with me. A ‘77, ‘86 and a ‘89. The first one wont apply.

My ‘86 service manual says:
“The lock-up mode is activated only in direct drive (3rd gear) and above a minimum preset vehicle speed. At wider throttle openings, where the 2-3 upshift occurs above the minimum lock-up speed, the lock-up shift will occur immediately after the 2-3 upshift”.

The lockup clutch is located inside of the torque converter. The only cars I’ve seen with Torque Converter Clutch (TCC) failures are in modified diesel pickups. In those, you have a torque beast of an engine pulling rigs weighting in at 10,000 pounds over the max capacity of their rigs - and the TCC is the weak link.
If you are worried about overloading your TCC, you can find many a aftermarket lockup torque converter to install, and can get one with a stall rating more in tune with your vehicle.
That said, the clutch disk in the torque converter has as much, if not more, surface area as the other clutch packs inside the transmission has.

The governor line pressure vs the lockup valve spring pressure vs throttle valve pressure is the 3-way fight controlling the lockup engagement.
I would recommend making sure the shift lever is adjusted correctly as well as the kickdown linkage adjustment first - for those two things fixes most transmission problems out there.

I was told if I change the ratio with out sorting the lock up I will burn the lock up out very quickly as full power can go through the LU clutch and it can't hold it.

I don’t believe that statement, at all.
A close statement saying your transmission kickdown linkage being misadjusted can/will burn the clutch packs inside the transmission real quick (not the TCC one, though),

My father had an old Toyota and it had an electric lock up clutch, it only came in when the car was under light throttle.

The Chrysler lockup system you have, has TCC engaged full time (when engaged, that is). Many newer vehicles cycle the TCC clutch on/off real fast - which makes a noticeable shutter or vibration when engaged.
If your TCC clutch is slipping - then you wouldn’t feel it engaging. If you can feel it engaging, then I doubt it is slipping. Note: this doesn’t sound like it came out right.

 

[Bruceynz]

Hi Bud,

I have not changed the rear end yet, I am still running the weak 7.25" which I am worried my 360 will now kill if I am not careful, my plan was to get the lock up sorted before the I did the rear end change to the 8.25" 3.21 so as not to damage the lock up. I will post the instructions from superior trans to have a look at and see what you think is going on. But for now here is the linage setup.

Thanks
Bruce

 

[Bruceynz]

instructions, hmmm seems the pictures get shrunk so makes it unable to read them on here

 

[Bruceynz]

This is out of my 1983 Service Manual, of particular interest is with a 2.94:1 ratio they did not use a lock up trans behind the /6.

 

[BudW]

This may help. It took me a while to figure this out. When on picture download screen, press the button for "full screen".
Those wide pictures, it might not help, though.

I need to see if I can print it your pictures, so I can read what it says.

I'm getting to an age where eyesight isn't what it used to be.

 

[Bruceynz]

Bud,

Take a look at my photo of my linkage set up of my previous post, I have had to put a bolt in the slot to make sure the kick down leaver goes all the way back at full throttle, I have now basically halved the slot length, if this going to be a problem?

Thanks
Bruce

 

[80mirada]

Make sure the lever goes all the way forward at closed throttle, also. The factory used a spring to keep it in contact with the throttle stud.