4g61t.org

First off my km210 trans is in bad shape and tax time is coming up so im trying to decide what to do.
ive been reading up on the forum and found the km210 is basically the same as a f5m31.
I also know the dsm f5m33 can be swapped in as well as long as you stay 25 spline and modify the shifter arms a bit.

Ive also been reading alot about all the parts in a transmission and how it all works (thank you youtube )
So with the age and abuse of everything out there im thinking of rebuilding a trans . Whether it be a km210 orf5m33.
i would have to buy a f5m33 first of course so i am interested in the km210 plus the shortgears seem good for autox

Rebuilding really seems like uncharted territory ive been looking for a while now and there simply isnt much info on it
on the dsm forums. Nor does it seem people actually know the specifics of what parts are really in these trannies.
im really hoping to spark some interestand get a conversation going.
i just cant believe everyone and their mom can rebuild an engine but nobody even knows how a transmission works
Except for the magicians at jacks,shep,tre etc.

Im really hoping some of you guys who actually go inside your transmissions yourselves can shed some light here

Is it actually true the km210 and f5m31 are same? How the same? Exactly?

Then how similar are the f5m31 and f5m33? For example what are some of the exact differences? Bearings,synchros etc.

for you experts how much interchangeability is there between these transmissions can i buy synchro parts for a f5m33 and put them in my km210?

I know for double synchros you need the double synchro oem gear or have yours machined. Can that stuff go in a km210?

what about hubs and sliders ? Will that stuff interchange from f5m33 into km210

oh and did email one of the experts above with some of these questions and the response i got back was simply
i dont know anything about turbo colt mirage transmissions

_________________
Black 1989 Colt GT with 4g61t. 200k miles and climbing. Rebuilt 2.0 in the works.....
14b, 450cc's, 3" exhaust, small fmic, all running on megasquirt version: DIYPNP
White 1992 colt-vista wagon 2.4, awd, auto (daily)
Keane

Best to think of it this way:

F5M31/KM210 fibrous syncros = easier engagenment, shorter life, 89 CSM/90 DSM style internals = oddball setup, GL4 only
F5M33/KM215 metal syncros = seem to last longer at higher RPMs, GL4 only, higher torque capacity, shares more internally and can be modified in many more ways.

Either rebuild one or the other, don't play with both. Gearing is nice of autocross in the KM210, but I suggest getting syncros that will last longer, more so with heel and toe in the metal contact variety - meaning the F5M33 FWD DSM transmissions. Components seem to be easier to source for FWD DSM transmissions, but there are setup much the same way in both transmissions.
5th gear is not the same between both and that is why you have to swap transmissions (to the DSM FWD) to get the EVO3 fifth to fiit and get you lower highway revs.

I just about put my head in a vice and gave it a whirl after nearly a year or more of agonizing over what I should do about transmissions.
I got my car 4g61t car with ailing syncros in the original KM210.
Installed another working but well used KM210 from West Virginia. Paid $125 US plus probably $150plus duty/brokerage.
Those syncros last a few years, but I would get lockout at higher RPMS. Shifter assembly worn out, and syncros.

Decided to go with the 91-92.5 DSM FWD transmission due to spline count and the ability to install a Quaife ATB LSD (from the AWD platform W5M33).
25 spline and with 2 sets of shims, speedo gear and ball and cage bearing, you just need to see a competent trans builder to make it all happen like it's supposed to.

There are many things to finesse when building a transmission and it's not something that I have wrapped my head around, nor do I care to.
Get it built correctly and pay someone, if this is not a forte. Trust me, there is LOTS that can go wrong and you will be putting money into this venture either way.

You will be swapping the shifter arms from the KM210 to the F5M33, and the roll pin pushes out towards the firewall. I used an air hammer of substantial potency and a modified bit.
Good luck drilling whatever it is made out of.
Also, I believe you swap the shifter cable brackets that mount to the transmission also.
My thread with pics is here: pics of scatter shield start here and This is the bulk of it

Install a 4G shifter assembly to a 3G base, with all new bushings. Mix and match the parts, it works out. Double nut the main bar, be generous with grease in between everything.
Brass/brass-oil or plastic, just get new ones for every pivot point. The thread details it all.

Work out a clutch and pressure plate combo for your driving style, and please realize that ultra light flywheels will cause all kinds of noise, input spline wear, gear chatter/rumble and idle nuisances. Aim for the 11+ lb territory, or help a light weight unit with an SFI silicone filled Fluidamper or ATI multi=piece. ATI requires removing the timing belt to install it because it incorporates the gear into the setup. Pricey on both counts.

I'm sure there is more I am not thinking of, or forgot to touch upon, so I'll leave it to the others to chime in.
I'm tired and need some sleep.

Don't go with the km210. Horrible gearing

From what I know the F5M31 supposed to have a internal improved design of the Km210 that's why they changed Transmission Codes, If you ask me they hold power/torque pretty well, almost like any F5m33, physically looks similar to the F5M33s found on 2gs but gear ratios are different, the f5m31 bell housings do not come with cooling ports so I would not recommend install it without making them first it's pretty easy, another plus is that they can accept equal length axles without problems like any 90-92 F5M33...

If you are worried about gear Ratios, I leave them here:
F5M31
1st-3.166
2nd-1.833
3rd-1.240.
4th-0.896
5th-0.731
R-3.166
F-4.322

F5M33
1st-3.090.
2nd-1.833
3rd-1.217
4th-0.888
5th-0.741
R-3.166
F-4.153

*If you look on front of the 2gs F5M33 gear boxes they also say F5M31, weird huh? Maybe internal quality it's the same on both and they just change gear ratios and differentials

_________________
91' Mitsubishi Colt 4G67T FWD "The Minion" - 12.26@118
94' Mitsubishi Galant GS 4g63 Swap "White Unicorn"
95' Eagle Talon Tsi FWD "Ernie's car" - 13.92@104 *Rest In Parts*

I absolutely LOVED the KM210 gearing. I missed it SO much when I swapped to a F5M33. Of course, my car was mostly stock, so not a ton of power. I noticed hardly any difference in gas mileage in swapping to a F5M33 with an AWD 5th gear. I found that the RPM's were so low on the highway that I had to lug the engine to pass people or increase speed, or even worse, downshift to 4th...thus negating any fuel savings. These engines are more efficient cruising in the 3,000-3,500rpm range at highway speeds. I'd say if you can build the KM210, go that route, because you can still use the larger turbo DSM clutch and flywheel with it...but if you're going for big power the F5M33 is a wiser choice.

_________________
91 GSX - 511fwhp and 352 lb/ft 25psi 110 octane, 7.68 @ 95.9mph 1/8th 21psi 91 octane, 11.93 @ 112.9mph, 117.7mph best trap speed, 20psi 91 octane
98 Volvo S70 T5 - DD

http://www.facebook.com/captaintonus

It depends on the power. But even around 425+ Hp that KM210 runs out of gear so quickly. Have to rev the hell out of the engine in the 1/4

thank you for your thoughtful reply Flying eagle
and thanks moulin13 for your insight into the f5m31. I find your experience very interesting
so is it that the 89-90 style internals is the reason the synchros from a 91-92.5 wont fit in a km210?
is it that they dont fit the gears?

your also right about parts availability. none of the major rebuilders list anything other than f5m33 stuff
im really wondering if somone has knowledge of the internal differences between the transmissions,gears,synchros etc. all everyone says is just that the f5m33 is better. thats not very detailed in finding parts options

my hope would be to piece together a rebuild kit for a km210 that at least utilizes all bronze synchros or better yet the ability to double synchro. otherwise its true that its probably not worth the effort

generic trans suppliers list rebuild kits with synchros for the km210 and f5m31 as the same kit
i wonder if those are fibrous synchros or the revised all bronze version

in terms of gear ratios turbogt it seems to me its a matter of opinion im not drag racing. im interested in a street car and autox car where quick pickup is most important. also i am no where near 400hp and dont intend to really ever have more than 300.

now if the f5m33 ends up being the best solution so be it id be happy with that.
i would like to keep this thread concentrated on the internals workings and specs of these transmissions so we can all learn more about them in general and then choose what the best solution is for ourselves.

_________________
Black 1989 Colt GT with 4g61t. 200k miles and climbing. Rebuilt 2.0 in the works.....
14b, 450cc's, 3" exhaust, small fmic, all running on megasquirt version: DIYPNP
White 1992 colt-vista wagon 2.4, awd, auto (daily)
Keane

I had no idea there was a difference between a KM210 and an F5M31, I thoutht and still think they are two different codes used for the same transmission, just like the KM215 is an F5M33.

Here is what TRE had to say about syncros's. Link

I know TRE had a listing of transmissions and their related torque values before impending gear failure, but I could not find it via google.

KM210/F5M31 do NOT have bronze syncros. You have to get into the F5M33 for that.
There is very little you can do to a KM210/F5M31 other than a stock rebuild.
There is a lot you can do to a KM215/F5M33. Here is a link to Jacks for a quick readup: Click me for FWD info

Things to keep in mind if you want to try rebuilding a tranny yourself. You'll need a press as some gears, bearings etc are pressed on/off. You'll need shims and maybe lots of them. The bearings have to be shimmed correctly and that means pressing it all together, test end play etc, press it all apart, change shims, repeat. Anyone can build an engine and half of them build it correctly. Not very many people can build a tranny and half of them can build it correctly. In my opinion, pay someone who knows what they're doing. Only way I'd say do it yourself is if you have a spare tranny that you can afford to ruin if you make mistakes.

I've run a KM210 and F5M33 behind my 1.6T and I like the gearing of the KM210 better. Even with a small turbo like my small 16g, the lag means it's on the verge of lugging at 60mph in 5th gear. I get better mpg with the KM210 and higher rpms at cruise. I think the only way I'd recommend a DSM trans is if you run a 2.0 or bigger or for whatever reason you need the taller ratios (top speed runs or running super fast in the 1/4 etc).

Maybe if you're running Auto-x and need good synchros to shift, maybe run a DSM trans then but I think the car will like the gear ratios of the stock trans better. I had English Racing rebuild my KM210 and it's basically a stock rebuild with crappy synchros but there isn't any other choice.

_________________
'89 Colt GT w/bigger than stock turbo
'91 Talon AWD w/bigger than stock turbo
'05 Dodge diesel w/bigger than stock turbo

TRE does know km210's as Jon once had a 4g61t. So based on that and that he had rebuilt several trannies for friends I went with him, although as stated there is only so much that can be done with the fibrous synchros and my shifting at high revs still reflects that. I also went with a Hyundai km210 final drive(4.0 vs 4.3) which equated to about 500 rpm less in every gear=nice. My current setup traps low 120's and rev's in 3rd are approx 7500 thru the 1/4.
Although not sure TRE is still operating as a year ago he wouldn't answer any correspondence.

I also ran a Hyundai km210. I pulled it from a low milage 89 sonata . It ran well and i liked it for DD. I swapped it out and the new owner is still using it mated to 2l.

They work!

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05 wrx wagon
99 Benz ML 320
91 eagle summit swapped - 6/4 bolt combo
94 Audi s4 - sold
88 Eagle Vista Turbo LX sedan, RIP

TRE Team Rip Engineering's FB page:

https://www.facebook.com/pages/TRE-tran ... 8038632987

I'm not endorsing, just passing this along.

Possible issues with cross border shopping, but have heard good things about them. Jon has owned more Mirage/Colts than you can shake a stick at IIRC.

Tre is a good company, but they take forever to respond and very hard to get ahold of.

i dont know either it seems they are the same.

thanks eagle for posting the links from jacks tre etc. i have read through all that stuff before and
i see that there is lots available for the f5m33s
i never was able to read anything verifying this. thanks. so if thats the case for the km210 i am longer
left wondering if they could be built up like a f5m33.
thanks for your input on ratios. i also dig the ratio of my km210 and i realize that longer gears might not be awesome for my goals (street car and autox) as long as im still on the 1.6.

your also saying that stock rebuild is all you can do which is great info since you even had your km210 rebuilt. now i know the only way to have a good built trans is to go f5m33.
i have to ask. how is the trans? how does it shift? prolly like stockk i guess ha ha. how does it handle high rpm shifts? and how long did it shift well?

_________________
Black 1989 Colt GT with 4g61t. 200k miles and climbing. Rebuilt 2.0 in the works.....
14b, 450cc's, 3" exhaust, small fmic, all running on megasquirt version: DIYPNP
White 1992 colt-vista wagon 2.4, awd, auto (daily)
Keane