4 spd tranny to 5 spd tranny

okay guys, that 5 speed i got is good to go. got the new mount and everything so i can get it put in tomorrow...im gonna do the bs work tonight like taking off the hood, fan, mount bolts and driveline from the 4 speed. does anyone have any tips for getting this tranny out? i plan on loosening the motor mounts so i can slide the motor up and forward a lil bit to get the top bell housing bolts but other than that im kinda clueless. if anyone as any tips or things i should look out for id appreciate it. thanks guys

I have done a little research on this as i too have a four speed. The four speed and the five speed have the same gear ratios for every gear with the fifth gear being an overdrive of .85:1, so you will not lose or gain anything by swapping but gas mileage.

First Gear: 3.566:1
Second Gear: 2.056:1
Third Gear: 1.384:1
Fourth Gear: 1.00:1
Reverse: -4.091:1

First Gear: 3.566:1
Second Gear: 2.056:1
Third Gear: 1.384:1
Fourth Gear: 1.00:1
Fifth Gear: 0.85:1
Reverse: -4.091:1

well you can check out my thread.

Their are 2 bolts at the top of the engine 16mm use a swivel and a long extension. Dont forget to remove the shifter befor anything else. It is pretty straight forword other then that to remove the trans.

to make a long story short, i dusted my rearend i think (ill know more when i pull it apart this weekend) does anyone know or have a book that has what the ratio is in the rearend? i put my 4 spd back in but since i might have to rebuild it, i might as well rebuild it with gears that will work best with my 5 speed. anyways, all im looking for is the 5 speed rearend ratio and the 4 speed rearend ratio. i know there were a few different rearends for both trannys, i dont know which id numbers to get off the tag to help id wich one i have.


quinn, i remember a while back you posted a website that get really good information about identifying the different rearends and possibly what the ratios were. do you remember what im talking about?

Thanks a bunch guys!

Yup, here you go Jeff. Just remember these are 4wd sites but most of the info will translate to the 2wd's.











If you need a new 3rd member check the junk yards, its gonna be a lot cheaper than buying a new one. I have a spare hoghead that has 3:88's (originally w/ 4 spd) it does need new pinion bearings.

thank quinn.

im hopeing that the gears are still good and just the bearings were trashed. ill probably know more this weekend when i pull it apart. i guess now would be the time to powdercoat the link bars and rearend housing. haha.

i had my Ujoint replaced and the mechanic said my pinion nut was really loose so he tightened it up. (it felt like it had alot of resistance on it but i assumed it was because of the new Ujoints)i made it about 10 miles the rear end go so hot it melted the seals and started to sling oil everywhere. i could hear crunching noises from my rear end binding up when i was loading it onto the trailer. took it back in there and he backed the nut off a little bit but and replaced the seal but i think the damage is already done. ill know more when its apart.

they say to use the 5 speed tranny over the 4 sp. tranny when putting a V8 in with those bell housing and clutch adapter kits they say the 4 sp. cant handle it like the 5 sp. can maybe the 5 sp. is stronger i dont know but im lookin for a 5 speed for my 302 instead of the stock 4 sp. but im runnin RX7 rear end

okay well i tried to decifer what i have in my truck as far as gearing ratio's. with the information off of that website and the model numbers off of my truck, nothing matches. for instance the model number i pulled off of my rear end pinon was b7xn which only the 'b' matches the table everything eles is different. where are the numbers on the rearend located? do i even have the right one? my truck is an 88 and on the decifer for the vin number it says its for 95 and earier but it stops at 89. the engine type for my 88 along with trans isnt even listed. i dont get it.

once apart, is there a way to calculate the ratio by hand?

sure. mark your pinion, and mark your hub. see how many revolutions it takes to turn it once. theres your ration(roughly.)

Numbers are on the tag at the firewall.