Gear ratio question, 5th gear popout

dirocyn · 10-13-2009, 01:24 PM

Flybike's 5th gear popout question, and espguitarist's useful link:

IMOC - Home :: Fixing 5th Gear 'Pop-out'

got me thinking. I'm getting ready to replace a clutch, and I'd like to fix 5th gear popout at the same time if that's possible. I have considered upgrading from a C50 (my car is an 86 na) to a C52, but I haven't located one as cheap as I'd like. But looking at that link, I might get away with just replacing the hub, fork, and 5th gear.

If I replace the 5th, I'd like to use a C-series 0.725 gear, (for instance, from a C53, as in the 1.4L CorollaD-4D) to give me lower rpms at cruising speed, plus a higher top speed. The C53 has the same 0.969 4th gear as we have in C50/C52, so I know it won't be too big a jump between 4th and 5th. My local self-service junkyard has 15 Corollas, so odds are pretty good I can find a C53 transmission (or better yet just a 5th gear from one) at a price I can afford.

So now I need a recommendation--is it even possible to swap gears between a C50 and a C53? Is it a straight swap, or will I need machine work? Would it be easer (or is it even possible) to convert a C53 transmission to use in an MR2?

dirocyn · 10-15-2009, 08:35 AM

Ok, come on people. Surely somebody knows--can you take a 5th gear out of a C53 transmission and put it in a C50? I know I'd need a puller, and possibly take it to somebody who has a press.

GrandpaGofast · 10-15-2009, 08:43 AM

" To boldly go where no man has gone before"
GP

mr2tim · 10-15-2009, 01:57 PM

Hey Diro

You might want to sit down with a transmission builder and discuss this work.

This person will have the rersources to obtain the specifications of the gear from the 53 and compare to the specs on the 52. If he knows his ass he can advise how much you need to machine the pieces to fit your application.

There are a number of perimeters involved in gear swapping as you are guessing about, and it is not an easy thing to research as you now are beginning to realize, right?

One bit of advice? Before you go out and spend hundreds of dollars on donor transmissions on the "urban legend" advice found all over the Internet, talk to that "experienced" rebuilder with your "advice" he will "talk the talk so you can walk the walk"

Toyz Raczing
A Toyota Race Team since 1989

YellowJacket · 10-17-2009, 11:57 AM

Yeah, especially when you could quickly find yourself approaching the cost of a C160 6speed swap. You would gain that top 6th gear you wanted for highway plus the sweet gearing ratio of the 1-5 gears.

I would have never paid the same money for my car outright as what I have in it right now.... but hindsight is 20/20 as they say. So that is why I say, if you are going in head first without knowing how deep the hole is, then a little research or common sense might tell you to do something different.

That is what compelled me to not look for another 5spd C52 tranny and instead put in a little more cash to solve the 5th gear problem along with a little extra upgrade as well.

10-13-2009, 01:24 PM	#1 (permalink)
dirocyn Cage Fighter Join Date: Mar 2009 Posts: 133 Thanks: 6 Thanked 12 Times in 12 Posts iTrader Rating: (0/0% )	Gear ratio question, 5th gear popout Flybike's 5th gear popout question, and espguitarist's useful link: IMOC - Home :: Fixing 5th Gear 'Pop-out' got me thinking. I'm getting ready to replace a clutch, and I'd like to fix 5th gear popout at the same time if that's possible. I have considered upgrading from a C50 (my car is an 86 na) to a C52, but I haven't located one as cheap as I'd like. But looking at that link, I might get away with just replacing the hub, fork, and 5th gear. If I replace the 5th, I'd like to use a C-series 0.725 gear, (for instance, from a C53, as in the 1.4L CorollaD-4D) to give me lower rpms at cruising speed, plus a higher top speed. The C53 has the same 0.969 4th gear as we have in C50/C52, so I know it won't be too big a jump between 4th and 5th. My local self-service junkyard has 15 Corollas, so odds are pretty good I can find a C53 transmission (or better yet just a 5th gear from one) at a price I can afford. So now I need a recommendation--is it even possible to swap gears between a C50 and a C53? Is it a straight swap, or will I need machine work? Would it be easer (or is it even possible) to convert a C53 transmission to use in an MR2?

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10-15-2009, 08:35 AM	#2 (permalink)
dirocyn Cage Fighter Join Date: Mar 2009 Posts: 133 Thanks: 6 Thanked 12 Times in 12 Posts iTrader Rating: (0/0% )	Ok, come on people. Surely somebody knows--can you take a 5th gear out of a C53 transmission and put it in a C50? I know I'd need a puller, and possibly take it to somebody who has a press.

10-15-2009, 08:43 AM	#3 (permalink)
GrandpaGofast Have tools, will cob it. Join Date: Jul 2009 Location: Mid Atlantic USA Posts: 131 Thanks: 33 Thanked 3 Times in 3 Posts iTrader Rating: (0/0% )	" To boldly go where no man has gone before" GP

10-15-2009, 01:57 PM	#4 (permalink)
mr2tim SUPERcharZed ToyZ RacZer Join Date: Mar 2008 Location: South Florida Posts: 690 Thanks: 2 Thanked 41 Times in 38 Posts My Google Map iTrader Rating: (2/100% )	Hey Diro You might want to sit down with a transmission builder and discuss this work. This person will have the rersources to obtain the specifications of the gear from the 53 and compare to the specs on the 52. If he knows his ass he can advise how much you need to machine the pieces to fit your application. There are a number of perimeters involved in gear swapping as you are guessing about, and it is not an easy thing to research as you now are beginning to realize, right? One bit of advice? Before you go out and spend hundreds of dollars on donor transmissions on the "urban legend" advice found all over the Internet, talk to that "experienced" rebuilder with your "advice" he will "talk the talk so you can walk the walk" Toyz Raczing A Toyota Race Team since 1989

10-17-2009, 11:57 AM	#5 (permalink)
YellowJacket 1985 N/A 6-Speed Join Date: Sep 2008 Location: Nashville, TN Posts: 271 Thanks: 8 Thanked 17 Times in 13 Posts iTrader Rating: (1/100% )	Yeah, especially when you could quickly find yourself approaching the cost of a C160 6speed swap. You would gain that top 6th gear you wanted for highway plus the sweet gearing ratio of the 1-5 gears. I would have never paid the same money for my car outright as what I have in it right now.... but hindsight is 20/20 as they say. So that is why I say, if you are going in head first without knowing how deep the hole is, then a little research or common sense might tell you to do something different. That is what compelled me to not look for another 5spd C52 tranny and instead put in a little more cash to solve the 5th gear problem along with a little extra upgrade as well.