those that have built a 518

[fatty]

How much of an issue is there with the aluminum planetary breaking in a 400-450 hp first gen? I was talking to Dave Goerend yesterday and he told me that it's not even worth it to build a 518 because of the aluminum planetary and something to do with the reverse band. He said when they still built transmissions in house, they wouldn't build on a 518 core but would take a 47re case and build that with a nonlock converter and other first gen parts because the 47re already has a steel planetary and updated reverse. I hadn't ever heard of that before and now I'm wondering if it's even worth it to try building my 518. It seems kinda pointless to me to get a 47re and the put non lockup parts in it.

[ellis93]

Sounds like a really good idea from someone who's commanding serious coin from their products,but honestly I'd probably just buy the parts and update what you have. There would be much less confusion in the build. There are a lot of pieces of information missing in that story.

[BC847]

I've effectively a beefed-up 48RE rotating assembly in my 46RH case.
- I don't do full-power launches in reverse.

So far so good.



Eventually though, with enough power, the thrust of the newer design planetarys (I can't think of the name for the angle-cut gears) could shove around the case guts resulting in failure.

[Sutter1stgen]

I've heard of the 518 having a bushing go out in the back of the case, which causes the drum to sag, and wear on the reverse band. But like stated above, sounds like a guy could just,,,,,,, re-bush the rear of the case.
I think a lot if the negativity people throw into this subject comes from lack of availability on a518s. I'm sure they aren't as plentiful as before.

[Tacoclaw]

"Helical" gears, I believe.

[txs]

fatty, the part that the drum runs on is the same thing whether you're talking 518 or 47, its the O/D piston retainer, and the bushing for the intermediate shaft and the bearing surface for the drum all in one. You can buy the front carrier in five pinion steel design for your 518. The only real upgrade to the 47 series was the double wrap L&R band which would be almost impossible to change the 518 over to. Do you need the double wrap rear band? idk, only time they apply is in reverse and L, they will handle quite a bit. When you take off from a stop with the tranny in drive the rear band does not apply.

[fatty]

So if I just make sure I don't launch in 1st(on the shifter) or in reverse I should be all right?

[FredS]

This is why most people just upgrade from the 518 to a 47RH. They can still be found reasonably priced. Fatty, why do you want to launch in L? if the VB is setup right, your shift points will be right at the RPM you want it to shift at, which on most 1st gens is around the 2800RPM mark, unless you have the fuel to keep power above that RPM.

There's nothing wrong with building a 518, but as most have already stated, its more cost effective to go to the 47RH for a long term goal.

[Diesel]

So is it better to pull down into L when taking off while towing? Or keep it in D and drive away?

[Fred S]

If not on a grade or in the mountains where you need to stay slow, leave it in drive.

[Diesel]

If not on a grade or in the mountains where you need to stay slow, leave it in drive.

Can you elaborate on the reasoning? Does pulling it into 1/L engage more frictions or increase pressures? And then in D it is less?

[Tacoclaw]

My *limited* understanding is that if you take off in drive it uses a sprag to hold the drum in place, and dropping it to low will engage the band to hold it in place. Whether it not it disengages that sprag when dropped into first, I don't know, but it must because if it's wasting bands then I would assume it's wasting that sprag right with it.

[Fred S]

Reasoning is purely what gear you need for the intended purpose. Manual control is typically only really needed on grades at very slow speeds, and typically with a heavy load behind it. Putting it in L does engage the Reverse band, thus taking the stress off of the sprag, or one way clutch as its also referred to. I've yet to see anyone break a sprag from launching with a load or at a track. Where they break is when you float from reverse to drive or drive to reverse without the vehicle stopped.

So back to the original question asked. upgrading to a 47 case, gets you the provision for the double wrap L&R band. That's the benefit. Compare the bands, and you'll see the major difference. Steel front 5pinion planetary can be done to either a 47RH or 518, as all 47REs for diesels already have it. If you can find a core 47RE front half for real cheep, which has the major internal hard parts, I'd go for it, as Goerend is saying they do.
Warranting broken 518s would get old real quick, as people tend to overdue it on load or power.

So decide what you will use it for, and decide if a 518 upgrade is enough for you're need.

[dazedandconfused]

BC do you have a link to your trans build thread?

[BC847]

BC do you have a link to your trans build thread?

My original rebuild here: http://www.dieseltruckresource.com/dev/ ... 60276.html

With breaking a shaft or so, I beefed it up a little here: http://www.dieseltruckresource.com/dev/ ... 018p2.html

Breaking another shaft had me do this mess: http://www.dieseltruckresource.com/dev/ ... 89281.html

Billet/alloy input, intermediate, and output shafts. All planetary gear-sets are the 6-pinion with steel carriers. With the exception of the rear clutch-pac, all the others are of an increased disc/steel count. The torque-converter is a custom Suncoast unit. I've screwed all around in the valve-body. Frankly, it could stand a professionals touch in tuning it.
An expensive PITA!