FWD 4 speed to 5 speed conversion question

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dmoneyswoop
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My tercel:: 1986 3 door hatchback
Location: Port Townsend, WA

FWD 4 speed to 5 speed conversion question

Post by dmoneyswoop »

Hi all,

Even though I don't have a T4WD I still frequent this forum for information. You all have helped me a lot with my Tercel hatchback project. I'm trying to build it to be a little quicker. Through my researching I have found that I want to swap in the 4AC. I also want to add side draft carbs and a cam regrind. I also want to swap in a 5 speed.

Has anyone had much experience with a FWD 5 speed transmission? Any certain quirks I should know about these transmissions?

My 4 speed transmission works fine, but I want that 5th gear.
xirdneh
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My tercel:: 87 tercel 4x4 wagon w/reringed engine, 83 tercel 4x4 wagon w/salvaged engine and 4.1 Diff's
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Re: FWD 4 speed to 5 speed conversion question

Post by xirdneh »

i have heard that if you get just the 5sp tranny (minus the differential)
you can use the diff you have but will need to drill hole in diff housing to accept longer shift shaft on 5sp
there is a chance your diff will already have the hole
if not its no problem to drill it
Love those Tercell 4x4 wagons but they sure suffer from road noise.
jimcrazy
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My tercel:: 1985 4wd 1986fwd 1983 4wd

Re: FWD 4 speed to 5 speed conversion question

Post by jimcrazy »

i went the other way,5 speed went out in my 86 fwd wagon could only find a 4 speed at the time,got the trans with front diff all together,only had to swap out the back end of the trans where the shifter linkage hooks on and the trans mount,the 4 speed have no idea what year tercel it came out of
dmoneyswoop
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My tercel:: 1986 3 door hatchback
Location: Port Townsend, WA

Re: FWD 4 speed to 5 speed conversion question

Post by dmoneyswoop »

How did your driving experience change between the 5 speed and 4 speed?

Just curious, what would need to be done to make these transmissions handle more power?
Jarf
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Re: FWD 4 speed to 5 speed conversion question

Post by Jarf »

Swapping to a 5spd won't help off the line performance, but it will drop RPM's on the highway, 5th is just 85% of 4th.
Sadly, there are no performance parts for the trannies and they are not compatible with any other cars
dmoneyswoop
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My tercel:: 1986 3 door hatchback
Location: Port Townsend, WA

Re: FWD 4 speed to 5 speed conversion question

Post by dmoneyswoop »

So the gear ratios between the 4 speed and the 5 speed are the same with the exception of an added gear?
Jarf
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Re: FWD 4 speed to 5 speed conversion question

Post by Jarf »

I don't have ratio specs in front of me to confirm that, but generally speaking, yes, 1-4 are same, 5th is an overdrive.
It wouldn't make any economical/engineering sense for manufacturers to do otherwise.
keith
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Re: FWD 4 speed to 5 speed conversion question

Post by keith »

I wouldn't make the conversion. It was during this period, late 70's through the early 90's that a few cars had both a 4-speed and a 5-speed version. In most cases, the fifth gears was in a separate housing as is the case with these transmissions. The gear ratios of 1-4 do NOT match between the 4-sp and 5-sp. In the 4-speed, forth is an over-drive.

But here is the real kicker, when I was reading magazines of the era, the 4-speed versions were quicker and got better gas mileage.
dmoneyswoop
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My tercel:: 1986 3 door hatchback
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Re: FWD 4 speed to 5 speed conversion question

Post by dmoneyswoop »

Interesting, maybe I should keep the transaxle that's in there. It started leaking around all the gaskets after I changed the gear oil a few months back. I'm going to take it out and redo the seals. Is there anything else I should do when I have the transmission and differential apart? I'm planning on replacing the rear seal on the engine while I have the transaxle out too.
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Petros
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My tercel:: '84 Tercel4wd w/extensive mods
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Re: FWD 4 speed to 5 speed conversion question

Post by Petros »

Those are all good things to replace while the trans is out. you might consider replacing the clutch if you need it, or at least the disk (you can buy a disk from rockauto for about $25). you will have it all apart anyway. if the clutch is fairly news than do not bother.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
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