SM465 Leak Help

[tc197]

Leak

[tc197]

Got a quote from a shop to drop the tranny, replace all the seals, and seal it all up for 800$. A lot higher than I expected. Should I just replace the tranny rather than drop 800$ into this one?

[Irish_Alley]

800 for a OD trans plus a few more for new driveshaft/s if you go with a 4l80e you will need about 500 more for a transmission control unit or at least 300 for a
"black box"

but if you dont want to or cant drop the trans yourself i would think of an overdrive trans that will save you some gas millage

[tc197]

After spending all day scouring craigslist and local places I found a clean sm465 that wasn't fully rebuilt but was gone through recently for 200$. Ill be headed to get it tomorrow and my plan now is to just swap leaky sm465 for sm465. With the leaky one out ill use it as practice to go through my first trans and then ill have a backup for down the road. Should be easy enough to drop the trans and tcase and swap the new one in but ill obviously find a way to screw it up.

Do I bother getting into the pilot bushing and throw out bearing while im swapping? Should I go even further than that and replace more?

[1967KaiserM715]

Throw out and pilot replacement isn't a bad idea.

One thing to make sure on is the spline and bolt pattern for both trans. This is the spline and bolt pattern to connect to transfer case. There are 3? Possible combinations for the sm465 transmissions.

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[tc197]

According to Novaks I should have a 32 spline in my truck now and the one Im picking up is also the 32 spline. I didnt realize there were different bolt patterns too. Ill have to look into that. Thanks

[1967KaiserM715]

The earlier 205 had a figure 8 sort of pattern the later 205 and 208 transfer case had a round 6 bolt pattern. 32 spline only came with the round pattern so you should be fine.

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[tc197]

Took me all day and night to get it but I have the new trans to swap in. So much work, so little time. Im also having a problem where a belt squeals everytime I start the truck for about 30 seconds. New PS pump and pulley, new water pump, belts are tight. Do I need to replace the belts?

[Irish_Alley]

FYI...
Earlier SM465
The earlier era of the SM465 include the 1968 - 1978 transmissions. There were both 2wd and 4wd versions. Internally, they are identical to each with the exception of the transmission mainshaft. The 4wd version of this mainshaft (or "output shaft") has a 10-spline output with a 2-5/8" stickout and an accompanying 4wd adapter housing. The 2wd version has a 35-spline threaded mainshaft compatible with a driveshaft yoke, and accompanying 2wd style tailhousing.


Later SM465
The later era of the SM465 include the 1979 - 1991 transmissions. A minor internal change of the 1st gear bushing and thrust washer occurred, in addition to a change from a shorter 10-spline, 4wd output shaft to a 32-spline 4wd output shaft - coinciding with the change of bolt pattern in the New Process 205 transfer case from a figure "8" input bolt pattern to a round, six-bolt input pattern. This pattern was also found on the 208 and 241 chain-driven transfer cases.


the round 205 only came out in 85ish but def in 86. gm still used the 10 spline 465 from 79-85 till the round came out then went to 32 splines. the other 4wd k10/20s that got the 208 were 32 splines

[tc197]

Well, plan is to pull the leaking sm465 and swap the new one in tomorrow. Hoping to get an early start as I don't know how long it will take me. Trucks on blocks in the front, trans is in neutral, removed the shifter.

Plan:

1. Drain trans and tcase fluid
2. Remove drive shafts
3. Disconnect any linkages/wires
3. Support trans/tcase and remove support cross member
4. Remove 1 bolt from trans to bell and get 4 more just like it, cut heads off, grind screwdriver slot in, and replace each bolt with a new headless bolt. (read this trick here on the forums)
5. Hook up jack with tranny adapter and secure to trans/tcase
6. Make sure the back of the motor/distributor is clear of the firewall and lower everything a bit.
7. Add support to back of the motor
8. Slide trans/tcase off the headless bolts until shaft clears bell housing.
9. Lower to ground and slide out from under truck.
10. Remove old sm465, reconnect new sm465 with new gasket between tcase and trans
11. Reverse process and reinstall.

Am I missing/misunderstanding anything? Thanks for all the help!

[1967KaiserM715]

Should be fine, I don't think you need to remove the shifter, but I think you do need to put it in gear(either L or 2nd) so the input shaft can clear the pressure plate.

And on that note, make sure you measure how much space you have under the truck, because of the bends in the shifter you need to move the tranny forward and down to get the stick out of the cab-if you can't get the stick out of the cab, it is really annoying to try and remove it after dropping it. I think I needed to put my truck on jack stands to clear the 700r4 I pulled.


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[tc197]

The shifter pops off easy and mines already off so i see no reason to leave it on.

Fluids have been drained
Shifter is removed
Both drive shafts removed
Disconnecting linkages and cables now

Considering pulling the tcase first and the trans after rather than both together. Any thoughts?

[Irish_Alley]

i would remove it. not sure which one you have the 208 weights about 80 lbs and the 205 is 140

[tc197]

Didnt see this until now. Tranny and tcase are out. Its a 208. I took them out together using a jack adapter and ratchet straps to hold them down. Im exhausted. Time to pull the old tranny off and reconnect the new one

[tc197]

Looking through my throwout bearing im seeing needle bearings way back in there all out of place. Must be my pilot bearing? Guess im going deeper than the trans and that made the pilot/throwout replacement question easy. Probably gonna do the clutch while i have it out too i guess