46RH (A518) Conversion project

M & J · December 05, 2017, 08:49 PM

Rick is evil. Yes.

Rickf1985 · December 05, 2017, 09:54 PM

W% W% W% W%

Sasquatch · December 11, 2017, 08:22 PM

Got the overdrive assembly rebuilt today. Converted the governor from diesel to gas specs. Got it all assembled then built a tool on the lathe to check the end play and thrust shims. I need to buy those tomorrow morning.

Everything in the donor transmission looked good and was within specs. I could have swapped the governor and ran it as is. But, I would have always been wondering in the back of my mind when it would fail, so better to do it this way. Probably the only thing that was iffy was all the seals and o-rings were old and hard. So good to get a new seal kit in there.

Sasquatch · December 11, 2017, 08:25 PM

The only thing left is to go through the valve body and install the shift kit and do final assembly into the case. Then it is a waiting game until dad clears his coach out of the shop so I can get mine in to do the swap and test.

Rickf1985 · December 12, 2017, 11:32 AM

Be careful with the 2-3 servo piston, mine was jammed and I had to drill it to get it out figuring it would not be hard to get a replacement.......................... yea, right. I used a Super servo and it works well but it is super touchy and I do not like the way I had to set the band looser than what I would normally like. Bottom line, try to stay with the stock piston. And if you happen to have a good spare piston.................................. W% W% W%

Sasquatch · December 12, 2017, 08:46 PM

Done. Now just to wait until I have shop space.

Froggy1936 · December 12, 2017, 09:39 PM

Hmm Done ? without paint ? Frank

Sasquatch · December 12, 2017, 09:57 PM

No one will ever see it. I may paint it, but is very low on my priority list.

Rickf1985 · December 13, 2017, 02:20 PM

You HAVE to do the silver paint! :)rotflmao :)rotflmao :)rotflmao :)rotflmao :)rotflmao :)rotflmao

lance6611 · December 15, 2017, 06:14 PM

Hi
Very new to the RV scene, love it. I would like to know how you maintained the center-line of the 2 pieces you welded and if you checked them again after welding. In my racecar transmissions I actually dial in the center-lines of the block and transmission with offset dowels. Do you intend to check the block to trans center-lines and if so how? I went the expensive bellhousing route with my dually but would love to copy your method. Great work by the way and thanks for posting this, really helpful.

Sasquatch · December 16, 2017, 11:01 AM

I lucked out, at least so far in my opinion. I had heard that the front casting of the 46rh was basically a 727 with different mounting holes, and I found this to be true. I chose carefully where I made my cut and the casting was exactly the same. It lined up perfectly. All the curves matched perfectly. I made before and after measurements from the 727 to the 46rh, and everything matched.

Now, how I am going to verify this is when I have the torque converter on the shaft, if it does not match perfectly the bolt holes on the flexplate, that will tell me it is off and I will consider it a failure and just order the ultra bell, cut off what I did and mount it up. The way I did it saved me $500. But, I may still have to spend that and get the ultra bell adapter if I did not hit it right.

I am 98% convinced it will be right the way it is, but I accept that it may be off.

lance6611 · December 16, 2017, 07:55 PM

I have reservations with using the casting, Maybe you could use a dial indicator on the crankshaft and install the transmission without the convertor and check the runout on the fixed shaft of the transmission just to check. It will bolt up with even .020" runout but the convertor bolts will constantly loosen up on you. Sorry to be a Debbie Downer, as I want to do the same thing to my 75 Indian. I think I might make some alignment shaft up that goes off an engines main bore and the transmission pump housing or other bearing bores in the tranny.
When do you plan to put the transmission in? Seeing as how you are a great guy who loves to share info, maybe you could explain the vacumn switch. I just had an on/off button and ya sometimes I forgot. lol

Sasquatch · December 16, 2017, 08:27 PM

I will do some checks as you suggest. That is a good idea. I can take measurements from the mounting flange to the fixed shaft on the 727 I remove and compare them to the welded up bellhousing. Should not be hard to fab up a fixture to measure it. I can do a plate that mounts to the face of the bellhousing and bolts to the torque converter on the 727. If it slides right on the 46RH, then I nailed it. When I have the 727 out I will have them side by side and I will figure out how to best measure it.

I will be doing the swap in late January.

Since I have a non lockup 46RH, there is only a two prong connector to control the overdrive solenoid. Power and ground. My circuit will be 12vdc at the dash to a toggle switch on my shifter. From there it goes to the vacuum switch at the manifold, then to the transmission solenoid and then to ground. The vacuum switch I chose is adjustable and I will set it to shut off (open contact) at somewhere between 5-7 inches of vacuum. That way, when the OD is active, and I am cruising, if I hit a hill and the engine vacuum drops below the set point, it will cut power to the OD solenoid. I can also override it by flipping the switch if I am on a gentle enough hill where it hunts between 3rd and OD, shutting off the OD.

Rickf1985 · December 16, 2017, 09:54 PM

Here is an idea for finding center. Lay the trans bell down on a piece of sheet metal and use drills that are the exact size of the bolt holes in the bell housing mounting points to just start a hole, more of a witness mark for hole center then a hole start. Do this for all holes. Take trans off of metal and draw straight lines across from side to side from the witness marks to determine center and then machine a hole of your choice dead center. This will be what you run the dial indicator against. Now drill the holes out for the bell housing mount bolts exactly the same size as the mount holes and bolt the piece to the bell housing. Mount the indicator on the input shaft and run the tip on the plate and turn the shaft and that will give you what you are looking for. I am guessing you will need to cut a hole for hand access off to the side the manipulate the gauge. I know you have machining equipment so that is why I am suggesting the rather involved plate.

Sasquatch · December 16, 2017, 10:15 PM

That is a great idea Rick. I have a rack of sheet metal I can use for that. I will work on that this week. I have a ton of dial gauges and mounts, so I can find something that will work.

Sasquatch · December 16, 2017, 10:31 PM

If it is out, I can possibly correct it with offset dowel pins. Thanks guys.

Sasquatch · December 17, 2017, 10:54 PM

I hit the jackpot. Through lots of searching I found the dimensions and layout of the BB transmission mounting holes and sizes.

I am going to draw this up in CAD tomorrow. From the cad drawing I can easily machine a plate to check how centered the input shaft is. This way I know my holes are all in the right places. I will machine two holes to properly accept the dowel pins so it will be tight.

Rickf1985 · December 18, 2017, 09:59 AM

Actually, Can't you use the factory separator plate? Nice find on the drawing. It has all the measurements you need for the center of the shaft.

Sasquatch · December 18, 2017, 10:22 AM

Quote from: Rickf1985 on December 18, 2017, 09:59 AM
Actually, Can't you use the factory separator plate? Nice find on the drawing. It has all the measurements you need for the center of the shaft.

I do not think there is a factory separator plate on my rig. Transmission bolts right to the engine with no plat in between. Maybe some had them. I dont know. Heck, maybe there is one on mine, I will have to look closer at the mating area between the two and see if there is one in there.

Rickf1985 · December 18, 2017, 04:40 PM

There is none on my diesel but it also has the SAE flywheel housing adapter to the Cummins engine. Totally different animal.

Froggy1936 · December 18, 2017, 05:27 PM

?Question How do you accuratly measure digital dimensions that large ? Micrometer ? 18 in range ? Frank

Rickf1985 · December 18, 2017, 07:06 PM

Generally you are only measuring sections so you would only use small sections. Most calipers go up to 6 inch. I have micrometers up to 8 inch but above 4 inch they are hard to handle. Only use them for rare work. Mostly you would use a indicator caliper and then measure that for big stuff.

Sasquatch · December 18, 2017, 08:05 PM

Well, on to another option. I took the drawing and converted it to a cad drawing. I then measured the radius from the center of the input to each mounting hole. I made a tool to find the center of the holes and have a 12" verneer caliper to get some initial measurements. Things just were not measuring correctly. I finally discovered that the center input shaft has a fair amount of side to side play that was throwing off the dimensions. I also discovered that the 727 bellhousing was off a bit from the dimensions I had. A few thousands here and there was enough to really mess with the measurements.

So, I am going to look for other ways to accomplish this. I may wait until I mount it up and measure the difference between the threaded holes in the TC in relation to the holes in the flex plate. They will be easier to measure.

I am open to other options if any of you have them.

Rickf1985 · December 18, 2017, 08:23 PM

It seems that they also reference the pump bolt holes, you should be able to use them for comparison to the bell housing holes.

Sasquatch · December 28, 2017, 09:32 AM

I am about 2 weeks out from having the indoor shop open up to bring my coach in and perform this mod. Fingers crossed everything works out. I will also be starting another thread detailing the other mods/upgrades and repairs I will be doing before this spring's trip to AZ.

I have new tires ordered and will be in next week, at that time I will be repainting the wheels, lugs and hubs. I am going with white wheels, black hubs and nuts as you guys have suggested.

Next will be upgrading the cheap aftermarket fuel pump system for my fuel injection to a complete system out of a mid 90's Ford F150/250 complete with plastic fuel line and Ford quick disconnects. This should be worlds more reliable and easy to get replacements on the road if needed.

Then an on board air system. I have a pump, 1.5 gallon tank, DOT air lines and fittings. It will also supply constant air to my air bag system installed on all four corners with a panel I made up in the drivers area.

I need to pull the heater box from the front of the coach and go through it with a fine tooth comb. It leaks air, makes noise, and the heat is horrible. It will be restored and updated to the best of my ability. I have all the sheet metal tools if I need to do major modifications to it. I already pulled the air conditioning evaporator out of it, but it needs more work. Probably a new fan motor, foam sealer on the flaps, silicone seam sealing, and a heater core flush.

I will be replacing my back up camera and monitor, as the one I have installed failed on the last trip.

Of course the transmission swap and hopefully a cheap e-brake solution I thought of. I am keeping that idea under wraps until I get the transmission out and take a look at it. It is a real long shot, but I have a machine shop..... (evil laugh).

I also have a few pages of projects that I make as I travel. Some are repairs, most are upgrades. I will see if I can address a few of them before I head out.