Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

Dear all

I have gmc truck 2wd and has gm sm 465 transmission 4 Manuel speed

The factory gear ratios are

1st : 6.55
2nd : 3.85
3ed : 1.70
4th : 1.00
Reverse : 6.:09

I would like to upgrade the ratios without and change in the main transmission body just need to change the rings inside the transmission

The ratios that I would like to have are

1st : 3.27
2nd : 1.97
3ed : 1.34
4th : 1.00
Reverse : 6.:09

So the changes will be only in 1st , 2nd and 3ed

Please note that the tire hight is 33 inch
The rpm up to 6200 rpm
The rear end ratio 3.73

I need help on that

Regards

Re: Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

Did you win the lottery or have a bucket of cash wasting away in the closet?
You'll need a ton of money to get a machinist to design, build and install new gears in your old case.
Why try to re-invent the wheel?
There's a bunch of nicely geared tranny's already available.

Re: Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

Sounds to me you just need a Muncie 4spd.

Re: Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

Geezer#99

Thanks for your reply acutely I don't want to build new one I just would have new rings and meager it to be installed in the gear it self I'm using the sm 465 since 1990s and I tried before many kind of gears so i want to find new way to use the same gear with the ratio that I need to be in the truck

Regards

Re: Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

J_knight

Thanks for you reply I try it before it's good but I still want the sm 465 but try to change the rings

Regards

Re: Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

You can't just swap in gears to get the ratio's you want with that tranny. They don't exist. You can have some made but it won't be cheap.

Re: Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

Geezer#99

How much it's going to cost

What is important for me is two main things

The body from out must be the same one as it's factory so not like the Muncie one
The transmission movement must be not like the Muncie up and down I want it be like the factory movement

I hope you get my point clearly ?

Re: Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

You can buy a brand new muncie m21 for 2100 bucks. That's one that's been designed and parts made for it for a long time.
Your new gearset will likely cost 2 to 3 times that much.
Or more!
You'll have 5 to 6 grand in a 300 dollar tranny.
If you find a skilled engineer/machinist to make you a set.
So you have a sm 465 with those gears. Those are the only ratio available. You want to change them. Open your wallet!!

Re: Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

What we are trying to say is that there are NO other ratios availabe for this trans, either GM or aftermarket. You would have to have someone engineer and machine a complete custom gear set. My initial estimate would be in the $15000 range, if you can find anyone willng to do it as a side job.

You want a top shifted trans with better ratios. You do not say if this is 2wd or 4wd. If 2wd the Muncie is an option, but you can get a 5/6 speed Tremec from Summit for aout $3500, or an NV4500 for about $800 out of a wrecking yard. You'll have to alter the drive shaft and the Tremec shifter may be in an odd place. OR you could add a Gear Vendor OD unit and get some interesting ratios.
4 wheel drive gets into a bunch of drive shaft and cross memeber moves. Best bet there is NV4500 from 88 up truck, get the t-case and memebers and shaft youkes, wil need custom shafts but not that bad. Shifter is pretty close to right spot.

But you will not get the other rations in the current trans without a boat load of money.

Re: Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

Nobody can answer that. It will be custom, one off, no other thing like it in the world. Its not even close to feasable unless you can custom machine the stuff yourself.

Re: Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

Over the years I've seen a few references about custom gear sets for the SM465, but it's been so long I don't have any company names for you. Likely they don't exist anymore anyways, and they were about $1200 PER GEAR, so you'd be looking at a significant amount of money.

Re: Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

Thanks a lot do you any good engineering can work on that and I will open the welt but I must now how is the success on that

I need to talk to someone now how to build that

Regards

Re: Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

Thanks for ur reply I don't think it's going to cost that amount 15000$ for sure it's less

The gear vendor not want I really want again I need the sm 465 factory body and movement used I just need to change the rings

Regards

Re: Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

Do you know companies can custom for me and build what I need

Regards

Re: Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

Try these guys!!
http://www.autogear.net/

Re: Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

:sumo:

This amount is great for me I can pay that

You must try to Squeeze your brain to remember the names

Thanks a lot for your reply

Re: Request and help to upgrade ratios of gm SM 465 Manuel 4 speed transmission
 

Thanks bro I will contact them and see