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View Full Version : rear end? Why not just gear and pinions?



Cougarcruisin
04-24-2005, 07:20 PM
Maybe I'm not educated enough to say this, but by CJ 05 I'd like to have the 3.73 gears in the cougar. But the more i research the more confused I get.

what I'm stuck on is...

Why not just purchase new gear ring and pinion sets for the 7.5 rather then buying a whole rearend out of a donor car.

Gear ring and pinion 159.99 (http://www.mustangtuning.com/mopepl3gefor.html)
or
$??? from a junkyard. (my junkyard is super expensive for anything)

I'd imagine it'd be a hell of a lot easier switching out the gears (although I dont have any idea how to even start), rather then tearing the whole rearend out, then replacing it with the new 3.73s.

Maybe i just dont know what I'm talking about. Maybe its cheaper over another route.

Any ideas or can anyone set me in the right direction of thinking?

btw

I have a pretty much stock 5.0l
w/ just headers, no cats, h pipe. and an intake.
thats pretty much the only mods done to it.

I've heard many of times to get the quicker acceleration then get the 3.73s. I wont ever really hit the 100mph for the top speed. So 3.73s seems to be the way to go.

Any suggestions and ideas would be awesome.

tbirdscott
04-24-2005, 07:54 PM
People swap rears to get the stronger 8.8" rear instead of putting money in to the 7.5". If you plan on putting down any power in the future a 7.5" is virtually useless.

Tbird232ci
04-24-2005, 08:30 PM
yeah dude, people grab the turbo coupe rears, because they have traction lock, they already have the desired gears (3.73 or 3.55), quad shocks, and disk brakes, on the stronger 8.8 rear

this is where its tricky, putting gears in a rear is not simple by any means, 95% of the time, i say take it to a shop, very precision work, and if youre going to get gears, its best to put a traction lock in, because theres no use of doing gears, and not being able to put it to the ground

doing a rear swap isnt really all that hard, untill you gotta plumb the brake lines

Cougarcruisin
04-24-2005, 08:33 PM
ya, sounds like a garage job....
ok so the gear and pinion is out... never tought about those situations.

Ok,
for those of you that went with the 3.73 gears, how much did it cost you to do everything? What est. cost should I be looking at?

V8Demon
04-25-2005, 10:42 AM
People swap rears to get the stronger 8.8" rear instead of putting money in to the 7.5". If you plan on putting down any power in the future a 7.5" is virtually useless.

Only rear end part I've ever broken on my 7.5 is the left side axle shaft (which is the same exact part as on the 8.8 ear). I got about 240 HP at the tires (around 290 Flywheel). They'll take some abuse.

Chuck W
04-25-2005, 10:57 AM
Unless you're doing clutch drops on slicks, the 7.5's will be good for most folks. You can get Trac-Loc units for the 7.5's and some of the earlier(83-84) TC rears had Auburn differentials instead of the Trac-Loc, which are much nicer IMO. The 7.5 is also quite a bit lighter too.

Ether947
04-25-2005, 12:02 PM
Unless you're doing clutch drops on slicks, the 7.5's will be good for most folks. You can get Trac-Loc units for the 7.5's and some of the earlier(83-84) TC rears had Auburn differentials instead of the Trac-Loc, which are much nicer IMO. The 7.5 is also quite a bit lighter too.

You wouldn't happen to know their weights would you? :D

Chuck W
04-25-2005, 12:10 PM
Not off-hand, but IIRC it is in the neighborhood of 75# difference between the two. It could be less though.....

Cougar5.0
04-25-2005, 12:14 PM
yeah dude, people grab the turbo coupe rears, because they have traction lock, they already have the desired gears (3.73 or 3.55), quad shocks, and disk brakes, on the stronger 8.8 rear

this is where its tricky, putting gears in a rear is not simple by any means, 95% of the time, i say take it to a shop, very precision work, and if youre going to get gears, its best to put a traction lock in, because theres no use of doing gears, and not being able to put it to the ground

doing a rear swap isnt really all that hard, untill you gotta plumb the brake lines

Yeah, I snagged a TC 8.8" for $150 at tht bone yard - was one of my better purchases.

JeremyB
04-25-2005, 12:33 PM
You wouldn't happen to know their weights would you? :D
http://www.foxtbirdcougarforums.com/showthread.php?p=6727&highlight=mooseballs#post6727
The weight difference is about 10-30 lbs.

Chuck W
04-25-2005, 12:43 PM
There you have it.. :p

EricCoolCats
04-25-2005, 12:49 PM
I don't buy that. It's definitely more than 30 lbs. I can pick up a 7.5" by myself all day...the 8.8" is a hell of a lot heavier, and I never move one without help from either a person or a floor jack. I'm thinking a 7.5" with a locking center weighs more than the typical open 7.5" we pull out of these cars. That would explain some of it. But 10 lbs., my ass. That is not right.

JeremyB
04-25-2005, 01:08 PM
I don't buy that. It's definitely more than 30 lbs.
Do you have any quantitative rather than qualitative data?

The largest weight difference seen was 45 lbs. That was comparing a complete Fox 7.5 to a SN95 8.8. It certainly isn't 80lbs.

Blown306Cougar
04-25-2005, 01:24 PM
That would explain some of it. But 10 lbs., my ass. That is not right.

you know your right.. your ass can't only weigh 10 lbs.. :raspberry ;)

just bustin your ball$ Eric or in this case ass..


on another note an 8.8 is much heavier and stronger then a 7.5..

some people may not agree.. but if i would have stuck with the 7.5 i'm sure i would have changed about 40 of them out by now in my cougar..

i've seen them blow up.. hell i destroyed my old 8.8 with 28spline axles.. anyway if your a person with a car like ours that is stock "155 HP" and you never even plan to do anything even a bernout.. it should last.. but if you plan to tool around and have a little fun and have more then lest say a bone stock motor... it will blow up!!! it may not happen today,next week,next month,or even next year!! but it will blow up one day alot sooner then an 8.8....i've seen both cases where it lasted a long time.. and the cases where someone whom transplants a more then mild motor over 200HP says "ahh screw it!! it will be fine till i get the chance to change the rear.. and goes ripping down the block and BOOM!! and get the car pushed back to the shop or backyard to change the rearend..

oh and yes by the way when i typed the word "backyard" in my mind i said it that way!! not backyad!!! and i'm still not ALLSET!! :crazy:

have a nice day eveyone


Nick

EricCoolCats
04-25-2005, 01:42 PM
When I rolled the stock 7.5" open 2.73 rear end out of the convertible, I picked it up myself off the jack without too much effort and kindly deposited it beside the garage. This is complete with drum brakes still attached, nothing else removed. The same afternoon I tried to lift the 8.8" TC rear onto the jack myself and nearly herniated myself. That's when I got help from a friend, with another as a backup to work the jack. The TC rear did not have anything removed from it (i.e. mooseballs) and I believe we left the brake hardware attached loosely. I know what I can lift, and what 20 lbs. feels like, and there was way more than 20 lbs. difference between the two relatively stock rear ends. When two people struggle to get one rear end in, while one person can handle the other easily by himself, that's telling you something. In fact, all 3 of us took turns trying to lift each rear end by himself, and we were all shocked at the weight difference of the 8.8". I don't carry a scale in my garage or we would have weighed them both. Is it 40 lbs.? I can maybe see that, although it felt like more. Right now I have a large plastic container filled with TC rear brake parts and can confirm that the rear rotors, calipers, brackets and rubber brake lines together weight more than a complete 11" front brake conversion, spindles and all (I have those in an identical bin next to the rear parts). Again, I don't have access to a large scale to weigh them...but I struggle picking up the bin with the rear components while having a slightly better time with the front parts bin. The rear discs weigh a LOT more than people think. That may be the weight difference right there, I don't know. It would explain a lot.

BTW, the old Visteon link isn't working. Any chance you still have the PDF?

JeremyB
04-25-2005, 02:01 PM
BTW, the old Visteon link isn't working. Any chance you still have the PDF?
Sneaky devils moved it here (http://www.visteon.com/products/automotive/media/axle.pdf). Those weights don't include everything. Probably just the housing, axle tubes, ring/pinion, and bearings. Everything else is common between the two rear ends.

The weight differences could very well be skewed by advocates of the 8.8". (i.e. I swapped a 1337 8.8 in place of my 7.5 so it can't possible weight much more)

I'll weight my 7.5 and the 8.8 that is going to replace it whenever I get around to the 5-lug swap (years? :D).

SirChirpAlot
04-25-2005, 05:16 PM
U guys are all weak.
i just put my 8.8 back in by my self and the help of a garbage can to rest it on and lower the car on the host. I frist droped my 7.5 that was not to bad to lift off and drop on the floor then pick up my 8,8 with upper and lower arms on and lift it onto the can.

But yes 8.8 is a tad bit more but its all in your mind just lift it and stop bitching.

Bob
04-25-2005, 06:23 PM
I just put an 8.8 in myself too, I used a jack though :) take your time put rear on jack, slide jack under car, connect lower control arms, get springs ready and jack up to the uppers... 5min job..

I'd rather put a whole rear in rather than stare at the insides of one. You need to set backlash correctly which I know nothing about.

Ifixyawata
04-25-2005, 07:30 PM
Yeah. Just do the whole axle. It's a ton easier.

And, I will say that the 8.8" is a heavy SOB. I had it in the trunk of my grand marquis and the car rode like a truck and you could feel EVERY bump in the road.

PS - I pulled the engine, transmission, driveshaft and rear end out of my car all at once with only a bungee cord and my teeth. You're all pu$$ies.

TurboCoupe50
04-26-2005, 09:21 AM
PS - I pulled the engine, transmission, driveshaft and rear end out of my car all at once with only a bungee cord and my teeth. You're all pu$$ies.

:laughing: :laughing: :laughing: :laughing: :laughing: :laughing: :laughing: :laughing: :laughing: :laughing: :laughing:

Thats right Ifixyawata, tell em how it is .... :D :rollin:

Tbird232ci
04-26-2005, 12:52 PM
it is about an 80 pound difference

i know V6 stang boys who will swap out their disk brake 7.5, for a disk brake 8.8, and each has said its about an 80 pound difference, one guy weighed it on his bathroom scale and ended up putting 5 lugs through the scale...woops

Chris1987LX
04-26-2005, 07:18 PM
I had a local speed shop install 3.73's in my 7.5. It ran me $300.00.

Chris

Go Roush
04-28-2005, 08:31 AM
I have a 7.5 out of a 85 Turbocoupe, with 3.45 gears and it is also traction-lok, It is probably something about what you need.

blakct
05-11-2005, 07:30 PM
Today I pulled the 8.8 out of my '88 TC parts car and put it on the bathroom scale (it's accurate) complete with brakes but no mooseballs. - 175 lbs. Then I weighed the 7.5 drum brake axle from an '85 stang that I threw in the car to keep it rolling. 145 lbs. Sure, there's no quad shock brackets and they're 1.5" shorter than a cougar axle but that's as close as I could come. Probably only a 3-5 lb difference between a stang 7,5 and a Cougar 7.5 due to the length and brackets anyway.

That's a 30 lb difference, all day long :hick:

jcassity
05-11-2005, 09:18 PM
this is where its tricky, putting gears in a rear is not simple by any means, 95% of the time, i say take it to a shop, very precision work

that was my first thought,,rear end assembly is a science and should be respected.

TurboCoupe50
05-11-2005, 10:45 PM
Today I pulled the 8.8 out of my '88 TC parts car and put it on the bathroom scale (it's accurate) complete with brakes but no mooseballs. - 175 lbs. Then I weighed the 7.5 drum brake axle from an '85 stang that I threw in the car to keep it rolling. 145 lbs. Sure, there's no quad shock brackets and they're 1.5" shorter than a cougar axle but that's as close as I could come. Probably only a 3-5 lb difference between a stang 7,5 and a Cougar 7.5 due to the length and brackets anyway.

That's a 30 lb difference, all day long :hick:

And there you have it.... It's also approx the difference I expected..

jcassity
05-11-2005, 11:27 PM
30lb difference
humm,,, thats info worth saving,, taking notes. :deal: