using crv and wagovan parts check my math please.
lavoy1
Banned
hi i will be using a 99 cr-v trans and transfer case and i will be using a wagovan rear diff, according to my research the front will be a final drive of 4.562 and the rear will be 4.533 this will require a slightly taller tire on the front as i will be using a solid driveshaft custom made by a shop since it seems that the oem shafts for the wagovan have gone extinct and after weeks of searching i believe them to be very extinct. any way when i do the math the tires seem to have to be exactly .15 of a inch different in height. this i believe can easily be done with air pressure rather then trying to find sizes that are that different. any way any input would be handy.
Comments
this is true
If you mean you are using an rt4wd one- spare yourself alot of troubles snag a 99 CRV one MT not AT
a solid drive shaft on the miss match gearing = major problems
math will work but without a VC you have no play. an end result of a busted diff, dive shaft, or transmission.
yes you have to customize the rear axels but you are already going for a solid DS. drop a little extra have the axels custom also.
lowering tire pressure is a good idea, what happens when the tires heat up? or cool down? and change the size.....
The 4.562 ratio in the transmission is to both the front and rear wheels. There's a step down in the transfer case to the driveshaft and then a step back up in the rear diff. Do some searching. The numbers are here on the board.
5spd CRV
Final Drive (transmission) = 4.562
Transfer gear (transmission) = .434
Rear Differential = 2.533
Auto CRV
Final Drive (transmission) = 4.357
Transfer Gear (transmission) = .393
Rear Differential = 2.533
the rear diff's are the SAME between auto's and 5speeds. The ratio differences are 100% inside the transmission (same as a rt4wd wagon) There has been a few people that have done what you want (CRV trans, Wagon rear end) and have approached it in different ways. 1st, you CANNOT run without some sort of "center diff" (Viscous Coupler from wagon, or TCD unit from CRV) doesnt matter if the ratio's were perfect, you would still destroy one, if not all of, the trans, driveline, rear end, axles. 2nd, there is one guy that i know of that is running a crv trans, wagon VC, and wagon rear end. (obx d-series lsd) He destroys VC's regularly and is currently searching for a different option because what he is doing, does not work. Im sure you all know of Epic Tuning and their new red civic coupe...CRV trans, wagon VC, (welded VC) and wagon rear end (welded diff) they run a tire that is .2 taller in the front. they cannot keep a transfer case in the car in this configuration. However, when they put a functioning VC in place of the welded VC, it works great (so far) I know its not much, but i hope that info helps you!
When a substantial amount of torque is put into the bevel gears in the transfer case, the very nature of bevel gears forces them apart. The housing is not strong enough. The aluminum splits/cracks/breaks. That's the same thing that happened to me with my RWD Wagon.
The output of the transfer section in the Wagon RT manual transfer case is .393 and the ear diff is 2.529.
I also read up on how to rebuild them on here but noticed that no one knows the exact amount of silicone fluid to use or even which silicone, I watched some videos on how to rebuild the coupler in the vw syncro awd vans and they have it down to a science weighing exactly the right amount of grams of fluid and the correct fluid.
I'm not good at formulas but if any of you are interested and feel like figuring it out I translated the formula and the fluid viscosity is 100,000 mm² /s ( ~ 70 € / 1kg) they also measure it out on a scale in grams rather then just fill it, it actually appears to only be about 1/4 full or so before they put the disk back in once the disk or in the level is still not all the way flush with the top.
Any way if some one can find out what that formula means I'm sure that will be the fluid we need.
I recently rebuilt my VC using the Dimethylpolysiloxane (Dimethicone) available from Sage
http://www.thesage.com/catalog/products ... icone.html
The viscosity is too low, 1000 cS., the vc does not transmit torque, even though it feels quite stiff when turned by hand. Further research reveals that the 3 viscous coupling fluids listed by Dow Corning (which are no longer available according to the distributor I contacted) range from 10,000 cS to 88,000 cS viscosity. My research indicates that the fluid used in the synchro video is 100,000 cS, the metric measurement is equal to centistokes (cS). Note that, while they weighed the dimethicone carefully, getting it all into the VC is like trying to empty a bottle of refrigerated honey.
I am still trying to find a supplier for the Dimethicone in the 60,000-80,000 cS range in a reasonable volume. So far i haven't.
As for the correct volume, this is what I did. The air in the coupler is intended to allow for thermal expansion without damaging the seals. I reasoned that the maximum temperature of the coupling must not exceed the maximum temperature for those seals. The Buna-n seals have a maximum temp of 240 deg. F., so I filled the VC completely, then placed it with the fill holes up and open in an oven heated to 200 deg. F. and let it soak for about 3 hours (until the Dimethicone stopped oozing out). I placed a catch pan underneath so Heidi wouldn't know I was using her oven. I then took the VC out of the oven, poured out just a little more to bring the level below the bottom of the fill hole, then let it cool overnight. The next morning I reinstalled the plugs in the fill holes. This SHOULD provide enough expansion space without going over.
The filling process will be very slow with the proper viscosity fluid, if and when I find it.
I hope this makes sense.
i found a place right here in my state that has the proper fluid 100,000 cst for sale i have to buy it a gallon at a time from them, i wonder if going even thicker would transmit more torque since as you noted going thinner transmits less.
1,000cSt light syrup
2,500cSt. pancake syrup
10,000cSt. honey
25,000cSt. chocolate syrup
50,000cSt. ketchup
60,000cSt thick molasses
100,000cSt. hot tar
250,000cSt. peanut butter
1,000,000cSt. paste/caulk
The thicker fluids that Dow Corning produced were 60,000 cS and 88,000 cS. The VW synchro rebuild was using 100,000. I have located 60,000 and 100,000, both selling by the gallon. I'm trying to sort out the potential difference in behavior of the two. The thicker the fluid, the more it will act like a solid driveline. I suspect that the spacing between the plates has a big effect on how thick the fluid should be and how the unit responds. The stuff that came out of my VC was extremely thick, I'm thinking of going with the 100,000. Since I only need about 1/2 pint for each of my wagons, I will be offering the remainder of the gallon for sale to the group.
Still trying to figure out how to fill the VC with something that thick. I may have to disassemble the stack, something I was trying to avoid.