Hi all.

I have been trying to sum up the strength of the 5 speed boxes, but can't seem to find any conclusions. I am asking because my current classic is fitted with a box with the TY754 casing, to be more precise a TY754VN1AB. A lot has been said about the different versions of the classic 5 speed gearboxes, but could anybody explain to me why the TY754 casing is stronger than the TY752, what was made diffent? Another thing is the internals. According to some sources the later TY754VN boxes, such as the TY754VN4AA and later the TY754VN6AA were stronger, can that be confirmed? Is that down to stronger parts being used? I had the TY754 5 speed box on my earlier refurbed some years ago and I could see that Subaru used a new part number for main 1-3 shaft. Is this the shaft that is fitted to the later TY754 boxes and this that makes them stronger?

Sorry for the rather long post, I am just trying to get some clear statement to why some say that "the later 5 speedboxes" can handle upto 400/350, while the older can't even go to 300/300.

Looking forward to your replys!!

Ras

 

5 speed box's tend to run up to about 350bhp and 350ftlb ish, but then your in the danger zone. higher milage box's wont do that much, mines shat 3rd gear running 258bhp and 280ftlb, yet some will do more than 350 and above but thast mroe luck than judgment.

shortversion is if your going for 340 or above then your gonna need a 6 speeder or a ppg box to make sure your not spitting teeth out the box.

 

But when you say that you crunched your box at 258/280, was that then a 752 or 754 casing? I am fully aware that the standard 5 speed boxes will not take the abuse in the long run, I am just a bit confused that all 5 speed boxes are in the same catagory. I myself have eaten my way through one TY752 box and two TV754 boxes, so I know they will not last ;-)
What I am trying to figure out in this post is simply, what is the difference on the TV752 and the TY754 casing and which of the TY754 boxes have the strongest gearset (if there are any differences apart from ratios).

/Ras

 

No one?

 

Really no one that know about this even after all these posts about 5 speed boxes?

 

My 130 000 mile 5 speeder was still hanging on when i got rid of the car, and it was running huge torque at the time

 

Hi Ras,

First of all I cant answer all of your questions, I have been running for the last 4 years a TY52 casing using a PPG 1-4 gear set with modified UK 5th gear, and a Qaufie ATB front diff, the engine has been producing in excess of 300lb ft, we decided to remove it earlier this year for a precuationery inspection, we changed 2 bearings, 1 selector fork, and 5th gear, (which had lost a tooth )

I might add the car does get used on the track, some 100+ laps of the Nurburgring as well as driving back and for to main land europe.

IIRC the TY52 casing has only 5 bolts securing it to the block, were as the TY54 casing has a further 2/3 bolts, the TY54 casing is also heavier due to its construction, so I guess under big power/Tourqe conditions this may become a issue.

Other than the above, the box has run faultless, at the end of the day any modifacation/alteration people make to there cars, will effect servicing/repairs costs, for me the intial outlay has proved more than good value for money, as I dont hanker after big power, handling/brakes is what I aim for.

Good luck with what ever you choose is wright for you.

John

 

Thank you for your feedback John.

Does anybody know if anything were changed in the later TY754 boxes to make them stronger? Or are the internals of all TY754 the same strength?

/Ras

 

Personally, i think i just got a good one

I put about 60 full blown drag starts down via mine as well over the past 6 years that i had the car, awesome lol, i have mates who have had 2/3 boxes in the 6 years and they were running less power/torque then me

 

all depends how u drive it matie..350/350 is a safe bet but thier are people that are running 400 on their boxes. eather i will be able to tell you after xmas wen i post my 400 project on..hope my box lasts or ill be eating my words

 

Thanks for the info :-)

My original post was actually more to get an idea of how many different designs there are of the 5 speed. I know that the TY754 is stronger than the TY752 boxes, but what makes some newer 5 spped TY754 boxes stronger than the older TY754 boxes?

 

I have cut and paste my post from another thread on a similar subject which may help.

The 04 WRX box will be a TY754VN4AA or 5AA which is not the uprated one which requires the male shafts it is out of a late 05 WRX and is TY754VN6AA these have been found to be able to handle up to around 400bhp/400 Lbs Ft. The casings are completely different to the other 754 boxes and are significantly wider around the driveshaft outputs. I have not seen a gearset out of the box but the box has been redesigned and I can only assume the reason these are holding higher torque levels is due to them being designed to cope with the extra power of the 2.5 WRX's.
I used a TY754VN5AA out of a 04 WRX last year running around 330bhp and similar torque. This was used in a stripped out RA using sticky tyres for a whole hillclimb and sprint season. It was launched off the line a couple of times

I have compared the 752 gearsets to the 754 gearset in the 5AA box and the 5AA gears are bigger

 

I'm selling a box from a 2006 2.5 WRX but the code doesn't match those above Arch.
Mine is TY754VG7AA I have to say it's meatier than any other five speed I've seen although it does have the push type clutch not a pull type clutch so there's no clutch fork pivot.

 

David at APi is your friend!

 

Thanks Arch, now we are getting near some of the info I was looking for. So at least now it's confirmed that some of the newer TY754 have stronger gearsets. Does anybody know from what model the stronger gearsets were introduced?
As mentioned, this is not a post because I am looking for a gearbox, this is purely to be informed. I have heard so many rumours about the 5 speed boxes and I am just trying to figure out what is right and what is wrong.

 

The 4AA and 5AA are definately stronger than the classic boxes. I also have gearsets from a 1AA and 2AA box but have not compared them to a classic set yet.

The 5AA is fitted to the 05 WRX as that is what is fitted to my road car which is a 55 plate WRX and also the type of box I used last year in the RA for a whole hill climb and sprint season, and I can assure you I wasnt gentle with it. I am not sure what the 4AA is fitted to but logic would say 03/04 WRX.

Daz you have PM

 

I thought my TY54 box was strong until this happened pulling in 3rd at 60 mph. Car is running 389/401 bhp/torque though. This was a TY754VN2AA box.

 

Oooooo..nasty!!

 

The 754 boxes up to and including 5AA are on borrowed time at 400 Lb's Ft, I am not saying they are strong but they are stronger than the 752 boxes so if used at this level as long as you know its a matter of when it breaks and not if it breaks then at least you are fore warned.

 

nods of agreement from me..........

 

That doesnt look that bad

 

Auch, that looks like something I have seen a few times before ;-)

Does anybody know if the driveshafts are identical on the TY754VN1-2-3-4-5 boxes or do they change?

 

All the same. The newage front shafts are the same as well. I changed my 1993 RA front shafts that had a damaged Cv joint to a set of 04 WRX shafts

 

Can I just ask will a ty754vn6aa out of a 05 wrx go into a 02 bugeye wrx to replace a ty754vn2aa mines running 348/322 but gearbox give way on a map tweek doing a power run

 

If it's from a blob WRX then yes