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Discussion Starter · #1 · (Edited)
Ok from what I've been reading on this topic. It's best to get a new set of gears and get them cryo'd and shotpeened. Anybody have prices for the gears. Also is it just 1st through 5th gear that I have to buy or will I need other parts??
 

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If I may ad my expereince: I wouldn't buy all new---let me describe why: Muleman and I have had numerous cryo treated trannies---some we sold, others we used. I think the key is not to cryo a tranny that has already seen turbo. The tranny in my car never saw turbo or nitrous---it was NA for its entire life, then we cryoed the tranny (also welded the case), and then turboed the car, and NEVER had a problem--- The car ran 15 pounds of boost everywhere, and has never experienced a problem.
If you have the extra money, it would probably be great to have new gears, but if you can get your hands on a tranny that has never had 5th gear pop out, and never saw forced induction, I would wager you would be ok----
JGY is great to help w/ trannies however (this is what I have heard)
Good Luck--
 

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I had my tranny cryo'd and shotpeened and welded by jgy. The tranny had only 50k miles on it and while my turbo was going in I sent it of to jgy. I think it took about 3 weeks total (with ground shipping both ways) and cost less than $500. Don't quote me on the price since I might be off...
 

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Discussion Starter · #5 ·
SOrry about the earlier Post. what I meant to say was does anybody have prices for new gears. I know JGY does cryo and shot peen thats who I was going to go with.
 

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When the time comes JGY is definitly going to do my tranny!
 

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Discussion Starter · #7 ·
Ok got a price for a new set of gears 1-5 from Courtesy Nissan with their internet discount. $615.41. OUCH That plus cryo and shotpeen from JGY 1115.41 plus shipping Damn!!. I think I'm just gonna use the gears I got now.
 

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IH8-V8 said:
If I may ad my expereince: I wouldn't buy all new---let me describe why: Muleman and I have had numerous cryo treated trannies---some we sold, others we used. I think the key is not to cryo a tranny that has already seen turbo. JGY is great to help w/ trannies however (this is what I have heard)
Good Luck--
This is good advice. If you are doing this yourself, its ideal to find a cryo place that does a multistep process which involves post cryo baking to near tempering temperatures (around 275-300 degrees) between cold cycles, this is better than just cooling and warming up to room temperature. I use 300 below and am trying a new place.

After cryo you can polish and deburr the gears on a scotchbrite green grinding wheel. Polsih the tops of the teeth and the sides. Don't take off a lot of material, just shine it up and deburr it. This helps stop the gear teeth from digging into each other.

Shotpeening is very crtical. There are millions of places that do it wrong. Putting gears in a shot blast cabinetent and randomly blasting them is not shotpeening. You need to go to a place that does mil spec or aercraft certifed shotpeening.

You want to hit the gears hard, at a alumin intensity of 0.020 or greater. This is as hard as most shotpeening machines can go. Use 330 hardened shot, RC 55-65 hardness. If you really want to be picky hit the gears with 220 RC 55-65 shot first to get in the splines of the input shaft and the very base of the gear teeth roots, then hit it again with 330.

This will give the gears a slightly matt sheen on the shiny parts of the teeth, its hard to see but in sunlight you can see it. If your gears look the same even when being looked at close then you got bogus shotpeening. Use redline shockproof heavy gear oil only.

JGY uses my process and my places to get stuff done. To my knowlege neither he or I have experianced any failures of transmissions treated like this since I figured out this procedure.

Mike
 

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Discussion Starter · #11 ·
^^^LOL man the Par guys would be pissed. I don't think it would though. Mike K would probably know the answer to this.
 

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Are the par gears ---intended more for track or drag?

From my experience--the cryo tranny works great for drag and street use---so maybe par is unecessary for drag set ups????? What are your thoughts? Is there anyone on the forum who has used the par for primarily drag use?
 

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blackb13 said:
Please don't tell me that this process makes the PAR gears obsolete.



Steve.
No way. PAR gearsets are the only way to have a reliable transmission if you are beyond the T25-T28 level of power, or the mid to high 200's. So all of the T3/T4 guys and bigger need them.

With decent power it only delays the end. So if you blow trannys every 10 passes you get 20 passes. Treatment makes a difference but it won't fix a weak design.

Mike
 

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choaderboy2 said:
No way. , or the mid to high 200's. So all of the T3/T4 guys and bigger need them.

With decent power it only delays the end. So if you blow trannys every 10 passes you get 20 passes. Treatment makes a difference but it won't fix a weak design.

Mike
I would not agree with this statement: PAR gearsets are the only way to have a reliable transmission if you are beyond the T25-T28 level of power---

My b13 sentra was over 400 hp at high boost settings, and never ran lower than 15 psi on the street. My friends and I did.....I don't know how many passess at the track ---well a whole season ---and the tranny is still working great.

I am not saying choaderboy2 is wrong----but does he have the par gear set? Where did he hear this? If he could provide some more info that would be great.....
 

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Yes, Choaderboy2 does have the PAR Gear Set. In fact he helped design it.

His statement is true. The only way to have a reliable transmission is to get the PAR set.

I am in the same boat as you IH8, I have put down over 400hp at high boost settings, and have been on my cryoed transmission for nearly two years. Although we haven't broken one yet, we WILL.

The question is not WILL you break the tranny, but WHEN will you break the tranny. Unfortunately it's inevitable, with such small gears and a flexy input shaft that is to short to engage the pilot bushing.
 

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I have heard good things about par---but I also have been told about a gentleman who broke the par on an NA set up--- I don't want to start that battle again--but my point is, if you, and I have been running the cryo set up---been happy with it---and haven't broke, then why spend THOUSANDS on the par? Unless it is intended more for a track set up? Just my thoughts.....
 

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IH8-V8 said:
I have heard good things about par---but I also have been told about a gentleman who broke the par on an NA set up--- I don't want to start that battle again--but my point is, if you, and I have been running the cryo set up---been happy with it---and haven't broke, then why spend THOUSANDS on the par? Unless it is intended more for a track set up? Just my thoughts.....
Peace of mind. Not being stranded in the middle of the desert or in another state during an SE-R convention :)

Regarding what you've heard about someone breaking a PAR tranny, I believe the problem was the input shaft had sheared. This part has since been redesigned with a new input shaft which I believe has a higher spline count.
 

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choaderboy2 said:
This is good advice. If you are doing this yourself, its ideal to find a cryo place that does a multistep process which involves post cryo baking to near tempering temperatures (around 275-300 degrees) between cold cycles, this is better than just cooling and warming up to room temperature. I use 300 below and am trying a new place.

After cryo you can polish and deburr the gears on a scotchbrite green grinding wheel. Polsih the tops of the teeth and the sides. Don't take off a lot of material, just shine it up and deburr it. This helps stop the gear teeth from digging into each other.

Shotpeening is very crtical. There are millions of places that do it wrong. Putting gears in a shot blast cabinetent and randomly blasting them is not shotpeening. You need to go to a place that does mil spec or aercraft certifed shotpeening.

You want to hit the gears hard, at a alumin intensity of 0.020 or greater. This is as hard as most shotpeening machines can go. Use 330 hardened shot, RC 55-65 hardness. If you really want to be picky hit the gears with 220 RC 55-65 shot first to get in the splines of the input shaft and the very base of the gear teeth roots, then hit it again with 330.


Mike, correct me if im wrong, but shotpeening is more beneficial for fatigue failure than it is to overload failure??
 

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coolgear said:
Mike, correct me if im wrong, but shotpeening is more beneficial for fatigue failure than it is to overload failure??
You are correct but with a powerful engine, you are going to fatigue the gears and break them a lot quicker.

Thats why it helps but its not a cure.

Mike
 

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Agh! Makes Sense--- Thank you----
 
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