Tko 600

[hauss]

Anthony, my tremec shifts fine reely no kidding. look at silver sport videos on how to shift a tremec I had already figured it out way before I saw the video. The only problem is the rail for 5th and reverse I will get this figured out and let everyone know. The tko I believe is the right trany for our cars, just got to figure out the pin issue. The roll pin is not the problem the two holes removing to much material from the pin is. In my opinion just need a upgraded pin thats all.

[cycleguy55]

Originally Posted by hauss

the top imege .

Those standard split pins are very weak compared to coiled pins. Spirol (and others) also have a heavy duty version you may want to look at for additional strength and avoid pin breakage. For example, the standard 5/16" Spirol pin has a Minimum Double Shear Strength of 5,500 lbs, while the same size heavy duty pin is rated for 7,800 lbs. I suspect both of those are considerably higher than standard split pins.



https://www.spirol.com/company/produ...od_d.php?ID=50

[hauss]

Not sure what you mean 3 rail internal rails. 1-4, 3 rails total are on top of trany with aremovable plate. 5th and reverse rail is what I would call internal and that is the rail that is cracked in half . Paul dosen"t comment on that rail nobody does I have looked all over the net I am the first that I am aware of.

[hauss]

Originally Posted by cycleguy55

Those standard split pins are very weak compared to coiled pins. Spirol (and others) also have a heavy duty version you may want to look at for additional strength and avoid pin breakage. For example, the standard 5/16" Spirol pin has a Minimum Double Shear Strength of 5,500 lbs, while the same size heavy duty pin is rated for 7,800 lbs. I suspect both of those are considerably higher than standard split pins.



https://www.spirol.com/company/produ...od_d.php?ID=50

sorry not the roll pin the shift rail is what is cracking into two pieces

[Gaz64]

That 5th/reverse rail internal is the largest of the 4 rails.

All 3 top rails are 5th/reverse, 3/4, 1/2.

The 5th/reverse internal rail is driven by an intermediate linkage lever.

I find it difficult to believe that rail could snap it half.

Any photos?

[hauss]

Originally Posted by Gaz64

That 5th/reverse rail internal is the largest of the 4 rails.

All 3 top rails are 5th/reverse, 3/4, 1/2.

The 5th/reverse internal rail is driven by an intermediate linkage lever.

I find it difficult to believe that rail could snap it half.

Any photos?

working on it

[hauss]

Originally Posted by gaz64

that 5th/reverse rail internal is the largest of the 4 rails.

All 3 top rails are 5th/reverse, 3/4, 1/2.

The 5th/reverse internal rail is driven by an intermediate linkage lever.

I find it difficult to believe that rail could snap it half.

Any photos?

[hauss]

here is another one

[hauss]

You believe me now this is the second time.

[kyleb]

I would give liberty gears or Tremec themselves a call.
I believe tremec had some metallurgy issues with some shift rails and that area is definitely a weak point.
They may even send you one gratis..

[Gaz64]

Yes, there's no doubt it does look weak.

Tremec needs to know about this, if they don't already.

Why does it have a second smaller hole, for another pin?

How hard do you select each gear, especially 5th in this case?

[kyleb]

Originally Posted by Gaz64

Yes, there's no doubt it does look weak.

Tremec needs to know about this, if they don't already.

Why does it have a second smaller hole, for another pin?

How hard do you select each gear, especially 5th in this case?

One hole is for the selector link pin. The other is for the roll pin that holds the link pin in place.

[olddog]

When steel breaks it is usually a combination of hardness and places left by machining that cracks propagate from. The harder the steel, typically the more brittle. These types of steel takes a lot more care in designing a radius verses a sharp corner. Also all tooling marks left be machines need to be ground smooth. It's like scratching a piece of glass to control where it will break with very little pressure. I have worked with some hardened tool steels that in the hardened state nothing can machine them. The wear of the the parts are amazing and the are super strong (wont deflect at all), but drop it and it will shatter like glass.

This all said, I would suspect that when they machine the hole in the pin they are leaving sharp scratches on a microscopic level. I would inspect the next new pin under as much magnification as I could get access to. If I found any spots that a crack could start, I would polish them out.

[Gaz64]

Originally Posted by hauss

Attachment 35217

I'm trying to understand what the 2nd small hole intersecting the large hole is for.

The larger hole has a linkage pin that the intermediate lever moves the rail with.

Where in this transmission are the shift linkage stops?

In other words, if I bang the shifter hard enough will a positive stop be there to stop me breaking selector forks etc?

[NRP/MN]

Coiled roll pins are stronger (bottom image)

[hauss]

Originally Posted by olddog

When steel breaks it is usually a combination of hardness and places left by machining that cracks propagate from. The harder the steel, typically the more brittle. These types of steel takes a lot more care in designing a radius verses a sharp corner. Also all tooling marks left be machines need to be ground smooth. It's like scratching a piece of glass to control where it will break with very little pressure. I have worked with some hardened tool steels that in the hardened state nothing can machine them. The wear of the the parts are amazing and the are super strong (wont deflect at all), but drop it and it will shatter like glass.

This all said, I would suspect that when they machine the hole in the pin they are leaving sharp scratches on a microscopic level. I would inspect the next new pin under as much magnification as I could get access to. If I found any spots that a crack could start, I would polish them out.

The edges on the new one looked like someone cut the hole with a plasma cutter very rough you may be on to something

[cycleguy55]

Bad design, metallurgy - or both.

[olddog]

Originally Posted by hauss

The edges on the new one looked like someone cut the hole with a plasma cutter very rough you may be on to something

If this is aftermarket, get one from Tremec. If from Tremec, I would call and explain the situation. They may have sourced this pin from a new supplier or any of a million other things that could have impacted quality.

If all that fails seek advice from a machine shop that works with hardened metals. They should be able to advise you better than I.

I once worked for a fortune 100 company that I could send a broken part to, and they could tell you exactly where it started to break from (usually multiple places), how hard the metal was (both throughout and on the surface, what the metal was, etc etc. They would recommend several options like using a different metal, machining changes, etc. Often you can go to a stronger steel and not harden it as much and achieve the needed strength.

The point of my rambling is that there are engineers and metallurgists that can solve any of these problems, but unfortunately we cannot afford them. However Tremec should employ at least some of the bottom of the class expert graduates. Maybe some middle level folks or higher, you never know. It's worth a shot.

[hauss]

You are wise my friend It is a $40 part that is going to cost me 10 times that much to have a machinist make for me. I know dam well it was made in china , assembled in mexico then, sold in usa . Wait a minute isn"t that what happened to the space shuttle? Just saying.

[cycleguy55]

Originally Posted by hauss

You are wise my friend It is a $40 part that is going to cost me 10 times that much to have a machinist make for me. I know dam well it was made in china , assembled in mexico then, sold in usa . Wait a minute isn"t that what happened to the space shuttle? Just saying.

It's probably not wise to buy parachutes or bulletproof vests from the low bidder.