transmission ratios

mike2

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Jun 11, 2019
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hampton nj
Hello everyone i have a 302 1978 coupe with 302 from 71 fairlane with cast iron 4 barell 600 holley stock exhaust manifold to 2" duals. manual trans is grinding, bad bearings . I have two transmissions with ratios , 1st 407,2nd 2.57, 3rd 1.66 , 4th 1.00 2nd trans 1st 3.50,2nd 2.21 ,3rd 1.43, 4th 1.0 have 3.00 rear street car use was wondering which trans would be better these are both rad trans Thanks
 
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LILCBRA

I started this morning by knocking out some studs
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Just going with ratios, I think I'd go with the second one for the simple fact that they are closer ratios than the first. The big question would be what are they both from? If one's from a 4 banger and the other a 6, will either one of them hold up to the torque of the 302? These transmissions are pretty notorious for not handling power very well.

Now if you have the expendable cash, the time, and a few skills, swapping a T5 is probably the most recommended route. If you're kinda stuck with going with one of the 2 4 speeds you have you'll have to keep a good eye on some areas of concern. Overall length, shifter location, pilot shaft length, pilot shaft OD and pilot bearing ID to name the important ones.
 

mike2

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Jun 11, 2019
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hampton nj
Thanks, i was thinking the 3.50 first would be better choice. They are both mustang ll trans the 4.10 is a rad -s trans 4 cylinders and second is a rad -f trans. Which is a 1975 year trans. Shows for any motor . Not sure there is difference in trans for motors besides ratios . I know trans are weak but i have two for free. Thanks would like to post video of running but guess it has to go to you tube first.
 

Enzio

Dang it. I was hoping mine would get 3 more inches
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As long as it's out you may want to consider a clutch, pilot bearing, and throw-out bearing.
 

jozsefsz

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Aug 11, 2013
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As long as it's out you may want to consider a clutch, pilot bearing, and throw-out bearing.
Well, provided you can find one. Minimally you'll want to be careful with yours, don't chuck it into the parts-bin or the trash or let it hit the ground unless you have a verified replacement on-hand.
 

Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
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I just put a new one in this summer. long build thread on this forum. I don't know how to show it here but look for Drivetrain-V8 stock 4 speed clutch. Should tell you what you need to know. And, I'm on here enough to answer questions if any.
 
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mike2

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Jun 11, 2019
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hampton nj
well well well , so transmissions out . the two transmissions i have 1 from a 4 cylinder and 1 from 1975 are different and won't work. input shaft wrong lenthg and size and tail shaft shorter on v8 trans, front input shaft for v8 has larger bearing and case for bearing is bored bigger on v8 so cases are not interchangable either. Hmmm someone did say to check this lol .My research didn't turn up dimensional differences between trans, just ratios .I am going to take a part v8 trans and see how bad it is , and either put new bearings in or might have to go for t5 swap. Was really hoping for trans swap. Didn't want to get this deep and expensive. anybody need 6 or 4 cylinder trans in nice shape.
 

mike2

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Jun 11, 2019
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hampton nj
I'm telling you...there isn't anything easy on a II.
Your right about nothing easy. Lol. Its fun to drive and lots of looks when it was out. But trans was really grinding had to do it. Maybe i will post side by side pics for info “ of what not works lol. “
 
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mike2

Member
Jun 11, 2019
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hampton nj
Decided to rebuild Rad W v8 trans , had bad rear main shaft bearing. Gears look great , ordered rebuild kit with syncros and tail bushing, and all seals. Was wondering if anyone knew if gear clusters are same shaft size as 6 cylinder trans . Might like to swap gears for better off the line .350 1st gear end ratio is still 1-1 on any trans, so bigger v8 input might fit.
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2Blue2

will be trying this sex one when I can find it
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don't have an answer but it is fun to see it getting fixed
 

extra_stout

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Cool! Somebody said that your tranny is the precessor of the T5... now i see the pictures, the similarity is really very high.
Let us know if the gear swap works or not. :)
 

mike2

Member
Jun 11, 2019
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hampton nj
so did some research and checking on swaping input shaft with 6 cylinder cluster and installing in v8 housing. first gear in v8 housing on input shaft is 25/30 teeth , 6 cylinder is 22 /34 teeth so mixing the 25 with 6 cylinder cluster of 34 is going to cause a gear mesh problem. i can now take apart a Rad trans pretty easily lol and i got a better condition speedo tailshaft gear. Just going to rebuild the Rad w to stock, bought parts from cobra trans $112.00 delivered for everything ,gaskets ,seals ,bearings,fork pads and shifter saddle . nice metal made in japan bearings factory had plastic insert in ball bearings.
 
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429MII

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Be advised....don't throw too much beer goggled money at the proverbial ugly stripper. Those rad transmissions are junk for any kind of performance use. It's the reason why almost every II used for performance has either a T5 swap or an auto.

Unfortunately, the M2 rad transmissions behind a V8 are a grenade with the pin pulled.. As Elmer Fudd once said.. You have to be vewy..vewy.. caewful not to damage it.

Any driving/shifting for acceleration contests will be it's downfall. Even the torque load with the revs up in first or second, with a 302 flexes these things like a 600 lb man on a rubber tricycle.

Ford put a decent 8" diff in V8 cars, but left the basically V6 trans as good enough, which has always baffled me. I think they figured the 302's 4 cylinderish 140 HP would not be able to damage it, but It's the torque ..not HP.. that kills these transmissions.

Drive it easy like a regular commuter car, and keep your foot out of it and it has a limited chance of survival.

...I say limited... because, as we all know, a 302 and a 4 speed in a mustang 2 is a lot of fun so it's literally asking to be driven harder, a little gas off the stoplight, oh-yeah... shift....tromp....bang!..clank....hey.. why won't it stay in second??, whirrrrrrrrr..ding..ding..tick...tick..tick..and... whats that weird noise??......hence the fate of almost every 2nd gear in every M2 trans behind a V8......good luck!
 
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mike2

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hampton nj
I know the rad isn’t great for too much torque, but for $112.00. Vs $1500 + for t5 swap, it will get it on the road again, v8 trans has beefier input and input bearing and shorter tail shaft , and gears in great shape, my 302 is probably 210 hp gross and if i use it right should last a while. Thanks for all replies . I’ll post a pic of it back together.
 
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2Blue2

will be trying this sex one when I can find it
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I'm liking the fact your pulling new life out old crap
Carry On!
 

mike2

Member
Jun 11, 2019
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hampton nj
Trans done went pretty good , put back in car , drives very good lots of torque . Glad i couldn’t change ratios , have 185/70/13 tires on car, revs 2750 at 60 miles an hour . I pushed to 90 mph . Man it was loud. Lol. Lots of fun to drive . Has great pull when romping on it. Think 15” tires will help ?
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