Final drive mix up

azerty

Supermoderator
Hello all,

I have my gearbox opened atm, but I'm totaly lost on a final drive problem.

So I have a Glanza C56 gearbox, which has a 3.72:1 final drive
axle has 18 teeth, diferential gear has 67 teeth

now, I got a final drive set from a 4age black top engine which is 4.05:1
Axle has 17 teeth, diferential gear has 69 teeth

From what I understood those could be swaped.
now my mecs told me both axle and differential gears from blacktop are bigger than 4efte one. so when he fit them, they are so tight that they don't turn anymore.

other strange fact, my mec told me, when he use 69 teeth differential gear with 18 teeth axle, it seems to be ok, while one is from black top and the other one from 4efte.

I'm lost and desperate... I'm about to just fit back 3.72:1 orginal 4efte final drive :(
unless someone can bring me the light
 
Last edited:

Texx

Super Moderator
Did the 4.05:1 final drive come out of a 6 speed transmission? Don't quote me on it, but I'm pretty sure that the output shaft from a C160 transmission won't fit in a 50 series box. I have a suspicion that the the distance or line of centres between the 2 axis is longer for the 6 speed transmission case than it is for the 5 speed case.

It's not a good idea to mix and match the final drive gears, even if they appear to mesh OK. The pinion and ring gears are a matched pair, the teeth are machined at a precise angle so that the contact pressure is equal along the entire width of each tooth as the gears turn and also to ensure that there is contact between both gears at all times. Any change to the pitch or angle of the teeth on either gear will likely result in the teeth being chipped or completely stripped from the gear.

It's only safe to swap the output shaft and ring gear when your 100% sure they're a matched final drive gear set for the transmission series your using, also the backlash must be checked (0.2mm would be the absolute maximum) after they've been installed into the front case.
 

Texx

Super Moderator
Which output shaft bearings were used? Did you use the bearings from the 4A box (I'm guessing C50/51) or the C56?

Did they look the same?
 

azerty

Supermoderator
we have changed all bearings and oil seals while opening the box. this was the reason we did open the box. we have placed same as original

when we use the original 3.7:1 glanza final drive, it works perfect. it is just that 4.05:1 finaldrive which doesn't fit for some weird reason :(
 

St_mu69

Fresh Recruit
Hi,

I just did this swap but its not only swapping the shaft itself!

You have to keep 4age gearbox and bolt your 4e/5e bellhousing to it. Then press drill and tap to install your tranny support!

I'm planning to use this C52 trans from a 95 7afe Corolla in my upcoming engine build. Here is what I had to do to get it to work w/ my 5e in my 92 Paseo.

So first I built these 'stilts' to get the mount surface level so that my drill would go in perpendicular to the surface.

P1010044-2.jpg


First I scribed where to put the first hole, in the middle of the boss.
P1010004-2.jpg


Then I laid out where the next hole would be by measuring the trans mount bracket. The holes are 40mm apart in the horizontal direction and 57mm in the vertical direction.
P1010005-2.jpg


You do not have much meat to work with here, as internal to the transmission the casting that forms the bosses for these bolt holes is not very large, so you have to get pretty close to the edge.

Here is a pic of inside the trans where the bosses are cast. There is one upper spherical shaped boss that is just outside the picture, and a large boss on the bottom. If you set up the mount bolt pattern too close to the bellhousing side the trans, you will be off of these bosses and into the thin portion of the casting. I forgot to get a better pic before I put the trans back together.

DSCN0752.jpg


Basically, this pic shows some lines that I scribed on the bosses that represent where the casting gets real thin inside the trans. The measurements are 57.5mm from the edge for the lower boss, and 18.5mm for the upper boss.

P1010028-4.jpg


Now back to establishing the bolt pattern. Centerpunch where the hole will go.
P1010008-4.jpg


Drill a pilot hole.
P1010011-5.jpg


P1010009-4.jpg


Tap drill the hole that will be tapped later. A M10-1.25 tap calls for a 8.75mm tap drill. I used a 11/32" bit, which is roughly equivalent. You want to go something like 21mm deep or so. I put a piece of tape on the drill bit to show when I was deep enough. Don't go too deep or you'll break thru, and have aluminum chips in the trans, plus create a leak path. If you do break thru, you'll probably have to use some RTV on the threads when you install the bolt.

If you are drilling this by hand, you might want to use a smaller bit, like a 21/64" to account for your hand moving. This is pretty critical as if you get the hole too big, you won't have enough meat on the threads, and if you go too small, the tap will not cut the threads and just strip them out as it's making them...
P1010014-4.jpg


Tap the threads w/ a M10-1.25 tap, which is the factory thread pitch. I had a semi-hard time finding this pitch. The sets I had were either M10-1.5 or M10-1.0. I had to get a new set from Harbor Freight just for this size, but was only like $17 or so. Lowes & HD did not have anything like this.
P1010021-7.jpg


P1010023-4.jpg


The bolt fits!
P1010024-4.jpg


Now I used that new threaded hole to put the bracket on and determine where to put the other holes.
P1010026-4.jpg


Drill the pilot for the second hole.
P1010028-4.jpg


Tap drill the second hole.
P1010031-4.jpg


Tap the second hole.
P1010032-5.jpg


Use the 2 holes to find where to put the 3rd hole.
P1010035-4.jpg


Here I used a bigger drill bit to mark where the 3rd hole should go. Don't go too deep.
P1010036-7.jpg


Centerpunch 3rd hole. Here you can see on the bottom boss and the top boss where I scribed some lines that represent where the bosses end inside the trans. Just to the right of these lines, inside the trans, the wall thickness becomes very thin.
P1010037-6.jpg


Pilot drill and tap drill the 3rd hole.
P1010041-5.jpg


Tap the 3rd hole
P1010042-5.jpg


And whala, you now have a mount that will work on your Terseo!
P1010047-4.jpg


Just FYI, I had a spare trans from a ~85 MR2 which was likely a C50. It did not even have the built up bosses necesary drill the threaded holes and mount the trans mount, so I don't think that's an option even if you managed to swap the shift mechanism around.

Next up is the bellhousing swap.

First remove this allen headed plug in the bellhousing.
P1010050-2.jpg


Here is where that plug is at on the top of the trans:
DSCN0716.jpg


Then remove all this stuff w/ a screwdriver and magnet.
P1010048-3.jpg


While the trans was semi-separated, which I describe below, I wanted to take a couple pics of where that spring and ball rides within the trans. Here is the shaft that it rides on,the ball bearing sits down in one of these valleys, and basically just serves to keep the shaft in that position once it's there.
DSCN0734.jpg


This is a pic of what the spring would look like in the bellhousing if you did not remove it before you separated the bellhousing. The ball bearing is missing and is likely floating inside your trans or on the floor, and will have to be retreived before re-assembly.
DSCN0762.jpg


Here is the shaft w/ the bellhousing removed.
DSCN0749.jpg


To get the bellhousing off, first get these 3 bolts out from inside the bellhousing.
DSCN0712.jpg


DSCN0713.jpg


DSCN0714.jpg


Remove the series of bolts around the perimeter of the trans casing.
DSCN0718.jpg


Use a punch and hammer and pry tool to begin to separate the 2 housings.
DSCN0513.jpg


When you begin to separate the trans, it will only go so far. Open it far enough to be able to see this and get a wrench in there. This is the reverse shift lever, which throws a gear into the main shafting to reverse rotate the gear train, hence you go in reverse. You have to get these 2 bolts out to separate the 2 housings. It's a 12mm.
DSCN0725.jpg


DSCN0737.jpg


DSCN0728.jpg


DSCN0739.jpg


Here are the 2 bolts.
DSCN0743.jpg


And once that reverse lever is disconnected from the bellhousing, you can fully separate the bellhousing from the rest of the trans.
DSCN0520.jpg


Here is the main portion of the gearbox that will be re-used. The differential is on the left.
DSCN0747.jpg


Here is the A-series bellhousing that is just aluminum scrap now, as far as I'm concerned...
DSCN0759.jpg


Here is the E-series bellhousing that will be used to adapt this A-series C52 to a 5e/4e/3e.
DSCN0763.jpg


Here is where the reverse shift lever will need to go on the E-series bellhousing.
DSCN0767.jpg


Also remember to clean or replace this magnet down at the bottom of the trans. I used some grease to hold it in place during re-assembly, since I held the bellhousing upside down to re-install it.
DSCN0769.jpg


Picture150.jpg


I took the opportunity to clean the inside of the trans while it was apart. Brake cleaner works very good, even better than carb cleaner, on this type of cleanup operation.
DSCN0770.jpg


Here I swapped the differential over to the bellhousing, trying to figure out the best way to reassemble this thing.
DSCN0771.jpg


I ended up putting the diff back in the main gearbox, and put it in this orientation. I found that the easiest to keep the reverse shift lever from falling out of position.
Picture158.jpg


So speaking of the reverse shift lever, keeping it in position was by far the most challenging part of the re-assembly. Here is what it would look like installed in the bellhousing.
Picture152.jpg


Picture151.jpg


And here is how I held it in place as I put the bellhousing over the input shaft with the other hand.
Picture156.jpg


So basically I held it in place with one hand, guided the bellhousing down with the other, then once the bellhousing was close enough, I used that hand to start the first bolt.
Picture159.jpg


Making sure to constantly check that the reverse shift lever didn't fall off it's pivot point or out of the reverse gear.
Picture164.jpg


Got the other bolt started.
Picture165.jpg


Then start tightening.
Picture168.jpg


Picture169.jpg


Once you have them tight, you can tap the bellhousing down closer to the gearbox, but only go so far...
Picture172.jpg


Now you have to put RTV around the perimeter to keep the gearbox from leaking.
Picture174.jpg


Picture175.jpg


Picture177.jpg


Then use some of the bolt holes to draw the 2 housings together.
Picture182.jpg


Some excess RTV will ooze out, which I cleaned up w/ a rag and then some carb cleaner on a rag.
Picture179.jpg


And that's pretty much it. You just have to replace the shift detent ball, spring and cap, which I'll show next time.
Picture187.jpg


[Edited on 18-3-2010 by Throttler]
 

Texx

Super Moderator
Awesome write up there, but that transmission appears to have a 3.72:1 final drive ratio not a 4.05:1.
 

azerty

Supermoderator
^^ indeed a 3.72:1 ratio on those pics above.

also, if all this is needed to swap, I will better keep the original final drive. Thanks for the nice long post. I'm sure it will help loads
I thought 4.05:1 and 4.3:1 were direct fit ?! :(
 
Last edited:

Texx

Super Moderator
my mecs told me both axle and differential gears from blacktop are bigger than 4efte one. so when he fit them, they are so tight that they don't turn anymore.

With just the output shaft and diff dropped into the front transmission case, will they turn or are they still stiff?

Are the output shaft covers (sat in between the front trans case and shaft bearing) the same between the 4A box and the C56?

Are they bigger as in they have a larger diameter or are the gears thicker?
 

Texx

Super Moderator
That doesn't make sense, are you sure it's a C series transmission? Does it physically look similar from the outside?

Are you sure it's not and E52 from a 4A-GZE?
 

azerty

Supermoderator
I didn't check the gearbox myself. it was given to me by a mec friend who told me he took it out of a 4age blacktop gearbox
 
Last edited:

Texx

Super Moderator
It may have been bolted to a Blacktop 4A, but it's possible someone had previously fitted a GZE box to the car.

Can you get a photo of the gearbox?
 

azerty

Supermoderator
I'll call him tomorrow for more info (it is quite late over here). That black top engine might have a gearbox swap before
so GZE gearbox internal wouldn't fit a 4efte c56 then ?
 
Last edited:
Top