A518 trans

Where is the best place to have a A518 trans supplied and built. No one in Australia has one.

Pat at A&A did mine, couldn't be better.

Thanks, I will give them a call.

The a518 is sometimes called a 46RH. You might search for that also.

Another vote for A&A.

I did not know that 46RH was another name for the 518. Thanks for that.

I make a trans brake & reverse manual valve body for the 518.

What type of car and what engine combination is this A518 in? I'm at a crossroads trying to figure out what O/D to go with for my 69 Charger. Tired of 3000 RPM's at 60 mph. I've been looking hard at GV, however if the A518 will fit behind a 440/515 stroker in the 625 - 675 horsepower range I'm interested.

*512 stroker. Sorry I fat fingered the keyboard.

Cars never received any of the overdrive, just truck.

All overdrives used the small block bellhousings except the diesel and they had a unique bellhousing which only fit the diesel and V-10. Some people continue to say they are a big block bell but that is incorrect. The diesel and V-10 received 12-3/4" converters and had a radiuesd shaped cutout at the bottom of the bell.

To fit a big block you need an adapter or have someone transplant a big block bell to your trans.

Overdrives based on the light duty 904/998/999 are called A500.
Overdrives based on the 727 are called either A518/618.

All the overdrives units look very similar to each other but those used behind diesels received a different spline angle for a few model years (so be careful mixing parts up) and some used single sided overdrive clutch discs (we eventually went back to dual sided).

Each family was first released as non-lockup then eventually made in to lockup.

Overdrives based on the 727 are called RH46 and RE46

Rh is hydraulic governor...RE is Electronic governor that is shifted by the PCM...

Overdrives based on the 904 are RH43 with the H being Hydraulic controlled governor.

Sounds like I need to stick with the Gear Vendors direction to eliminate all of the complexity. Thanks for the info.

Or put a third peddle and a 5spd in it.

We never used the designation RH46 or RE46 - it was 46RE or 46RH. We went to this designation after program launch - at launch they were called 500's, 518's, 618's.

We never ever offered a 43, only 42 or 44.

The PCM doesn't "shift" the trans - it only controls governor pressure on the RE units - the valve body shifts the trans between gears and in to OD.
On the RH it only controls the OD.

Splitting hairs - not really - any of these transmissions will shift manually in to each gear except OD.

Two things to keep in mind as you decide which way to go; the Gear Vendors OD ratio is not nearly as good as the 518. .69 vs .78. That is a big deal. And the 518 is available with converter lock-up.

There are calculators that will compute the RPM difference with your particular inputs.

Now, the converter lock-up may not be happy with the full power of the big block, but that really shouldn't be an issue. How often would you want to go to wide open in OD?

The 518 probably is somewhat more complicated to find and assemble for a big block, and nearly as expensive to boot. But the better final drive ratio makes it worth the extra effort in my humble opinion. Check out the calculators and see if would be worth it to you, too.

I want the four speed for my dually pickup which will be a daily driver and sometimes used for towing. Motor is a stockish 318. Diff is dana 70 which is being rebuilt at the moment with a power lok and 3.54 R&P

If a stock engine and not towing much weight you may want to consider one of two things.

Use the A500/42-44RH so you get the 2.7 first gear with that 3.54 rear.
Or move up to a 3.7 or 4.1 rear with the A518/46RH.

I have an extended cab 93 diesel with 3.54 rear and 47 w/o lockup - it can haul 9000+ lbs but it labors from a standstill and I have to stay out of overdrive up long grades or get a good running start.

I'm converting the trans to lockup this spring but moving to a 3.7 or 4.1 axle so I can carry more weight and get away from the light a little easier and leave it in overdrive.

Will the A518 trans survive a 700 hp engine in a 68 B body?

To the same level that a properly built 727 will- provided you don't hot rod it with OD engaged. Transmissions are really rated on torque output not horsepower anyways.

Pro Trans builds and has the adapters to put a 518/46RH behind a big block. Darren is installing one in his Coronet project. They have picts on their Facebook page from Sept 13.

So, this is an out there question. If I were to change to intake, carb, and put electronic ignition on an OBD2 magnum, would the transmission shift shift manually through 1,2,3? This is a SHTF scenario I have wondered about.

RH will shift fully auto 1,2,3.

RE will launch in 3rd with electronics dead since in default the governor solenoid is not being modulated ( so you develop full governor pressure ) so if you pull it in manual low it should launch in 1st then you can upshift manually.

Not the greatest for control but if it hits the fan you can get home.

Thank you very much sir.

Thanks J_Body. I think I read that the 518 was hard to fit in a B-Body, but can be done. I'll try to find the Pro Trans FB page.

GV makes a version for the PG (now) that splits gears, making the 2-speed a 3-speed with the overdrive, but also creating an intermediate gear between 1st and 2nd.
This can be done manually with a 727 conversion + GV, not sure if it's possible to do electronically (rather than try to juggle both controls).
The results for a 727:
1st 2.45:1
1st + GV 1.91:1
2nd 1.45:1
2nd + GV 1.13:1
3rd 1.00:1
3rd + GV .78:1

Correct me if I'm wrong here, but don't the first 3 gears go through an additional clutch pack in the 518s? A clutch pack that must release for OD. Without proper attention, that could be a point of concern that 727s don't have.

The power from the trans goes through the over running clutch (ORC) and direct clutch in the overdrive unit. I have never seen a failed ORC and direct clutch in the over drive as long as the trans was assembled correctly. The same direct clutch and ORC is use daily in the diesel units as the gas units.

The direct clutch is also used in reverse and is used to slow the vehicle down on coast in forward gears.

The clutch that needs proper attention is the overdrive clutch because the correct shim must be used on the OD piston to time the release of the direct with the application of the OD.

Are there any trans tunnel mods needed in a B-body for the 518 trans?
I know it's a pretty large amount of work in an A-body.

Even though the Gearvendors is only a .78 overdrive I think it would be good enough for me and an easier install. And I like how it will handle full power for an occasional highway brawl.

That's kind of what I was thinking. I have 3.73's with a CRT 727 and I'm turning around 3000 RPM's at 55-60. I know GV is only .78 vs. .69 but if I can keep it around 24-2500 at 70mph I'm good.

The last year the Dodge Cummins package used the 48RE OD trans was 2007. Like I stated earlier the geartrain in the OD unit was pretty much the same between gas and diesel.

For 2007 the Cummins made over 600 lbs. ft. of torque. Max GCWR was approx. 20K.

I don't think your torque and vehicle weight will stress the OD like the Cummins will.

I'm a fan of the 518. I have one behind a 512 stroker mated with an Ultra Bell. Between the bell, converter and transmission I've got about $1800 into it. OD shifts are controlled with a pressure switch and a vacuum switch. If you've already got a trans built by CRT though I'd be inclined to go with the GV too.

Good question.

Yes

Darren at ProTrans built my buddies A518 for his '66 Coronet, needed quite a bit of work to the tunnel and floor to get it in.
He has a 470" motor, bottom 11's on motor, low 10s on juice, his has a lockup convertor.
I have a GV in my '70 Cuda, only had to trim the trans crossmember some and put a few dents in the floorboard to get it in.

Can they be built to tow in OD and live? Say a 5500lb truck towing a 8-9K loaded car hauler?

Read my earlier post - the over drive unit is pretty much the same from gas to diesel - and the Cummins with this trans can haul 20k lbs.

Use ATF - 4 and nothing else. Put a trans temp gauge with the pickup in the pan and make sure you have a good cooler. You'll be fine.

I've towed my 30' enclosed at around 12K lbs. with a 47RH and a 48RE with never a problem. Never turned the O/D off. I used to tow about 5K lbs around with my 5.2 Dakota and a 518 (46RH) and had no problems with that either.