85 SM465 Transmission swap question
 

I am looking to swap out the transmission on my 85 C20 2WD from a SM465 manual to a better highway manual. I know you guys know these trucks. What would mate up to the 5.7L SBC 350 with more highway gears? Any suggestions?

What transmissions were available for NON-hydraulic clutches for the 350? Possibly one off a malibu, el camino, C10, or other? PLEASE HELP.

Re: 85 SM465 Transmission swap question
 

They made a 4 speed stick shift that had overdrive. A833? Anyway it is pretty uncommon.

Not sure if that came without a hydro clutch.

NV3500 is a good bet. Only came Hydro clutch though.

Re: 85 SM465 Transmission swap question
 

I have the A833 in an 82 K25. It's a mechanical linkage on it.Like was posted above,bit more rare but a nice little tranny.They were available as a hydraulic clutch as well.

Re: 85 SM465 Transmission swap question
 

I am presuming that you are looking for an overdrive trans. There are several routs you can go. If you need to retain the mechanical clutch, then I would recommend the NV4500. Keeps the low first gear like the 465 and give you an overdrive. Plus it is a heavier duty trans. If you would decide that a hydraulic clutch could work for you , then an NV3500 would make a nice choice.

Re: 85 SM465 Transmission swap question
 

The MY6 New Process A833 is about the only OD manual linkage clutch option.

I have 2 NV4500 transmissions. One is factory and one is a conversion...
Adding a Gear Vendors Overdrive to the SM465 will give you the same OD as the NV4500. It'll end up being much less time and around the same money spent... And you'll be able to tow in OD.

Re: 85 SM465 Transmission swap question
 

An 85 would of had a hydraulic clutch from the factory.

I second the NV4500.

Re: 85 SM465 Transmission swap question
 

Yeah. My 85 & 86 did but the OP was asking for manual linkage options...

Re: 85 SM465 Transmission swap question
 

These are great options. Thanks! I'll have to double check the clutch on the 85. I swore it was a manual linkage, but I may have been thinking about my 78.

I'm interested in that Gear Vendors overdrive. I'll check that.

I'm sure I'll have some questions once I double check it. Thanks again. I'm sure a hydraulic linkage would open up a work of possibilities.

Re: 85 SM465 Transmission swap question
 

So it is a hydraulic clutch. So my question now is for 5 speed options? I don't need to haul anything.

I would like to keep the cost as low as possible, so has anyone mated a c1500 5 speed to an 80s 350? If so, did it require any mods?

Re: 85 SM465 Transmission swap question
 

The NV3500 will handle the power output of a stock mid '80s 350. Max torque on the NV3500 is 300 ft/lb. Towing is basically out with that tranny. The gearing is more like a car tranny than a truck tranny.

The SM465 is essentially a 3 speed with an additional Low... the NV4500 has the same gearing with the addition of an OD gear.
The NV4500 is a heavy beast like the SM465. This swap can easily run into the $3000 range. That's the first reason the Gear Vendors is a good option.

You can tow with the NV4500 but... DO NOT TOW in 5th gear. This is where the Gear Vendors OD unit blows either 5 speed out of the water... You CAN tow in OD with a Gear Vendors unit without blowing the OD all to pieces.

If I had the 76 to do over I'd do a Gear Vendors OD unit...

If you must have the NV4500...
The 96+ transmission has the internal slave cylinder. The 93-95 unit has an external slave similar to the 85 but low on the RH side. Mating the slaves to the 85+ MC with a hybrid hydraulic line is part of the fun... I used a 96+ unit.
93 only has an extra low L (1st). Extremely rare so you prolly won't see one.
Make sure the *$&% salvage yard includes the bellhousing and shifter... No bellhousing? Don't be shy... Tell em why the sale just evaporated.

Re: 85 SM465 Transmission swap question
 

Im researching the same swap,
I dont tow, and just want a commuter rig not a rockcrawler,
I had a T-18 in my Bronco and swapped in a NV3550. and I love it.

its perfect for street driving.

the SM465 totally sucks for daily street driving, even with the addition of the aluminum top cover and short throw shifter.

heres some info I found, it seems that if you have a 6 bolt Tcase with a 32 spline input shaft, then its a direct bolt in swap.:


http://coloradok5.com/forums/archive.../t-284816.html

The S-10 NV3500 will not work for your application. While they will bolt onto your engine, they use a 5 bolt round bolt pattern for the transfercase instead of 6, and the shifter is right at the very tail end of the transmission, putting it up through your floor right about where your center console sits.

You need an NV3500 from behind a 4.3L V6 or 5.0L V8 (and rarely, the 5.7L) from a 96+ K1500. Absolutely avoid any NV3500 with an external slave cylinder on them. Not only does the slave interfere with your front driveshaft unless you've got a bunch of lift, but they are also extremely weak, and break very frequently even with just light and normal use. They also use a very crappy shifter assembly which frequently falls out of gear.

In about 96 they switched to an internal slave transmission, which is what you want to find. I am not sure exactly when they switched it, but there are two versions of shift rails. One is a single rail, and the other has several rails. You want the version with a single rail on it. They are the strongest version of the NV3500 from 88-98. GM continued using the NV3500 until at least 05, possibly up until 07.5. These transmissions are the ultimate in strength, and came behind 4.8L V8 engines which make more horsepower and torque than a Vortec 5.7L. I have one from an 04 in my K5, and have had no mercy with it power shifting and dumping the clutch over and over on it while mud bogging at full throttle with my 6.2L turbocharged diesel engine offroad, with poor gearing and 37" boggers with lockers. No signs of failure at all, no unusual noises etc.

Swapping them in is not a difficult task. They bolt straight in place of your SM465, using the same transmission crossmember in the same position, using the same mount even. They all have a 32 spline 6 bolt round pattern so you can use an NP241 or NP208. NP205 would not be a good choice, as there is no place for the shifter bolt. The clutch is the same as your SM465, no need to change the flywheel, disc or pressure plate. You need to use the hydraulic throwout bearing, of course. The shifter on these trucks sits a few inches back of the SM465, requiring you to cut the floor back a bit, and patch it up at the top. If you want to use the stock shifter boot, you will need to move the NP208/241 shifter back a few inches and shorten the shift linkage under the truck to match. To match the hydro clutch, I personally retrofitted a 93 K3500 bolt on type master cylinder onto my truck. I drilled a hole through the clutch pedal and used a 1/2" bolt with the head cut off / hole drilled through for a hitch pin to attach the linkage to the pedal. I have heard rumours, but have not tested just yet (give me two weeks...) that you can simply splice an 85-91 stock master cylinder to the clutch hose for the internal slave and use it without any trouble. Try at your own risk, you have to buy the master and the slave to get a new hose from GM. The reverse light wiring is a plug in kind of a deal, same connector as your SM465.

Let me know if you have any other questions or run into trouble!

Re: 85 SM465 Transmission swap question
 

Alot of that stuff doesn't apply since you are 2WD.

98-05 S10 NV3500 have the shifter 6 inches further rear-ward. Earlier S10 versions have them in the same location as the 1500 trans.

Re: 85 SM465 Transmission swap question
 

but the 96 and older versions are unreliable, according to everything Ive read,
weak syncros, weak bearings, weak shift rails.

but youre right, for a 2wd it should be an easy swap.

Re: 85 SM465 Transmission swap question
 

Hatzie,

I am considering this NV4500 swap for my SM465 , Just curious about not towing in 5th gear?
This was the main reason for my interest. Do you have first hand knowledge of problem while towing in 5th?

Thanks Desert

Re: 85 SM465 Transmission swap question
 

I believe not towing in 5th gear with the NV4500 was related to extremely high torque engines like the Cummmins 6BT. Towing in O/D would cause the 5th gear nut to back out resulting in loss of that gear. There are fixes for this issue but it may be a non issue behind a 350.

Re: 85 SM465 Transmission swap question
 

Thanks

Re: 85 SM465 Transmission swap question
 

There is also the Ranger Overdrive option for guys that tow and like shifting....I was considering this option versus the NV4500.

Re: 85 SM465 Transmission swap question
 

Another option is to swap 2.73 gears. However, I don't know if it can be found in 3/4 ton axles.

Re: 85 SM465 Transmission swap question
 

2.73 gearing works quite well with the SM465. Still tows decent too. Won't be the fastest thing around, but no such thing as "fast" and "budget" together.

Re: 85 SM465 Transmission swap question
 

I am both surprised and not at the NV-4500 misinformation in this thread...

Introduced in '92, cast iron case, 5-speed OD, top loading, dual PTO ports, external slave mounted low on passenger side (GMT-400 platform has front driveshaft through same area on driver's side), ratios as follows: 1st - 6.34:1, 2nd - 3.44:1, 3rd - 1.71:1, 4th - 1:1, 5th - 0.73:1, R - 6.34:1. Unchanged in '93. Unchanged in '94. Changed in '95 (same year D*dge introduced it): new ratios: 1st - 5.61:1, 2nd - 3.04:1, 3rd - 1.67:1, 4th - 1:1, 5th - 0.75:1, R - 5.61:1; some still external slave, but new bellhousing-case bolt pattern matching D*dge pattern and internal slave/throwout bearing assembly introduced at some point in '95. (AdvanceAdapters states that they have encountered an early low gear ratio '95 MY case with new bolt pattern on case). Other changes later on internally, reverse lockout, and some other small doo-dads, can't find clear documentation on when/what changed.

Re: 85 SM465 Transmission swap question
 

There's some confusion on the "super granny" 1st. Dodge had 5.61:1 1st/rev in 93. I'm not sure whether they ever had the 6.34:1. I don't have documentation that shows it. Allpar claims the 6.34:1 was a GM-only thing and only through MY 94. I know there were 5.61:1 units on MY 94 trucks... I bought one thinking I was getting the 6.34:1 ratio 1st for a 2wd tow rig. Optional ratio or early MY 94 production when there were still a few in the pipeline from 93?? Don't know. The likelihood of an unmolested Dodge pattern GM NV4500 with 6.34:1 1st/rev is low.

The change from external MT8 to internal slave MW3 was likely close to the 95 96 MY production split.

I was unaware there were Dodge pattern trannies with external slave bellhousings. If they exist it makes getting the original piece, still attached, even more important.

The MW3 got reverse synchros in 1998 or 99.

I stand by my comment on 5th gear towing. The retaining nut can back off and screw up the mainshaft and the gear. It's a known issue...

Re: 85 SM465 Transmission swap question
 

Good info in this thread , I was trying to keep the stock clutch and cross bar.
I thinking about the "Advanced Adapters" kit which looks like it has everything I need for my 2WD swap.
I will modify the trans cross-member and driveshaft

Attachment 1261184

Desert

Re: 85 SM465 Transmission swap question
 

In the owners manuals in these trucks, Its says not to tow in fifth gear.