Passon Performance 5-speed

-
Your Duster sounds a lot like what I would like to do in the future. Going to wait until the 360 gives out, and I get the 38 going. I keep telling guys that in 5 years, not many are going to be doing 340-360 upgrades, but it will be cheaper and get more power out of a 5.7-6.4 3rd generation hemi. Ok, it's not a real hemi to the old farts like me, but it does have power. Mate it up to my upgraded 904A and down the road one goes. Just my opinion, of course.

Even now it's getting harder to find LA engines anymore that don't need a full rebuild, I've "moved on" to Magnums since they're the most economical way to re-power an old Mopar. I can definitely see G3 Hemi swaps becoming more popular over the next decade.

BTW after doing a bunch of research that "not a true Hemi" G3 chamber is actually a MUCH better design than the classic Hemis; all the flow with none of the crappy low-speed combustion issues which in fact was the main reason the 426 Street Hemi was killed off.
 
So if its od that most people are chasing and the cruising ability at lower revs why not use the od a833?..
I know most guys are gonna critisize what i ask ...ans go on about ratios..but if its od ur chasing ...its a lot cheaper...

The spread between the gears reminds you every time you drive it that it's a crutch fix. That's why. Shift from first to third when you're in a hurry, see how that works out for you, because that's the OD4 in a nutshell.

I had wanted to do this swap for a long time but can't see myself swinging that kind of money for a transmission, a 5-speed no doubt when 6-speed Tremecs are readily available. IMO the only real benefits are not having to cut the floor and a transmission that looks factory (aside from that big bulge on the back ???), pretty nice on a Mopar with some pedigree but my Duster is just a 318 car so... T-56 swap for 1/2-2/3 the price of an A-855 and put the rest of the money into my G3 Hemi swap. A member on here recently even started selling new crossmembers for T-56 swaps into Mopars.

Yep, and the Passon lets you go back to bone stock (can you say "resale value"?) in an afternoon.
Not to mention the five speed is suited to most street cars just fine.
 
The spread between the gears reminds you every time you drive it that it's a crutch fix. That's why. Shift from first to third when you're in a hurry, see how that works out for you, because that's the OD4 in a nutshell.



Yep, and the Passon lets you go back to bone stock (can you say "resale value"?) in an afternoon.
Not to mention the five speed is suited to most street cars just fine.

LOL my car is already wayyy past "go back to bone stock in an afternoon". But if it was an original 340 4-speed car it would be a completely different story.
 
LOL my car is already wayyy past "go back to bone stock in an afternoon". But if it was an original 340 4-speed car it would be a completely different story.

The closer my car gets to yours, the more I look at the six speed, but for now, a drop n swap five speed sounds great
 
Has anyone had gear clashing when shifting gears? What kind of gear lube are you using?

I've had some clashing when shifting into 3rd gear on my A855. I was initially using a 75w90 GL5 gear oil. Then I got a note from Jamie saying to use 75w140 GL5 and after changing I got some clashing going into 2nd and 3rd. ie seemed to be getting worse. (I've got about 5000 miles on the tranny)
After some e-mails back and forth with Passon, Jamie sent me a bottle of Lube Gard ATF Friction Modifier (p/n 61910) to add to the gear lube. I was surprised it was for ATF and after some more e-mails, I was told that they have used this with success to improve gear synchronization.
I also questioned why they specified a 75w140 GL5 lube instead of a GL4 manual transmission lube. (A GL5 lube is usually specified for differentials and has a totally different friction modifier package than a GL4 MT lube.) I was told that the GL5 75w140 performed better behind very high HP engines (ie turbo etc). ie it needed a higher viscosity oil to maintain an oil film between the gears.
My engine is a basically stock 6.1 SRT8 Hemi so I'm going to use a GL4 Manual Transmission lube ( probably Amsoil MTG 75w90: Manual Transmission & Transaxle Gear Lube 75W-90 )
I was also told they have changed the synchronizer design a bit as the tranny evolved (I was # 4- a very early one) (Interesting to note that the A855 has carbon fiber blocker rings.)
I was also sent this interesting article of MT gear lube. http://www.widman.biz/uploads/Transaxle_oil.pdf which confirmed my engineering assessment that I was using the wrong lube.
Now I have to wait until spring!!!!
Jim

I've had the Cuda out for a short drive after changing the tranny lube from a 75w140 GL5 to a 75w90 GL4 transmission oil. The clashing is virtually gone. I need to drive it some more under different conditions to ensure that has solved the clashing problem. I have not added the "Lube Gard" additive yet.
Jim

IMG_4699 c_1280x600.JPG
 
Even now it's getting harder to find LA engines anymore that don't need a full rebuild, I've "moved on" to Magnums since they're the most economical way to re-power an old Mopar. I can definitely see G3 Hemi swaps becoming more popular over the next decade.

BTW after doing a bunch of research that "not a true Hemi" G3 chamber is actually a MUCH better design than the classic Hemis; all the flow with none of the crappy low-speed combustion issues which in fact was the main reason the 426 Street Hemi was killed off.

In the past 2 months, I've been to quite a few car shows and there have been more and more Gen 3 Hemi swaps. Several at each car show such as at Spring Fling at Woodley Park, MATS, the Edelbrock Car Show, and Mopars in May at CSDR. I'm wanting to jump on the bandwagon too, although I do have a Magnum sitting on the stand in the garage.
 
I've had the Cuda out for a short drive after changing the tranny lube from a 75w140 GL5 to a 75w90 GL4 transmission oil. The clashing is virtually gone. I need to drive it some more under different conditions to ensure that has solved the clashing problem. I have not added the "Lube Gard" additive yet.
Jim
Glad the oil change looks to be a promising solution to your problem. I have been on the A855 list for about two weeks shy of six years now and want mine to work correctly when it finally arrives. Every one that is currently running and getting the bugs ironed out is encouraging to me. Please keep us informed on your gear clashing issues.
 
I've had the Cuda out for a short drive after changing the tranny lube from a 75w140 GL5 to a 75w90 GL4 transmission oil. The clashing is virtually gone. I need to drive it some more under different conditions to ensure that has solved the clashing problem. I have not added the "Lube Gard" additive yet.
Jim

View attachment 1715177561
Did you use synthetic 75w90 GL4 or standard?
 
I used synthetic. Manual Transmission & Transaxle Gear Lube 75W-90
I've had the car out again for several short drives and the gear clashing is definitely gone. Seems like Passon got some bad advice from Lucas about what type of oil to use. Based on my research and experience - do NOT use a GL5 oil in the tranny. GL5 oils have friction additives specifically meant for rear differentials. GL4 oils have a completely different additive package that are meant for manual tranny's.
Jim
 
The video focuses on viscosity but doesn't talk about characteristics of friction additives. Also, Jamie's A-855 tranny uses carbon fibre blocker rings as opposed to older style brass rings.
 
My wish would be that Jamie could get past the faulty parts supply issue so he could get more transmissions out and I could finally get one to put some lube into!
 
Jamie has had a terrible time since he started this project with parts supplier problems. Sadly these are all US suppliers.
 
I used synthetic. Manual Transmission & Transaxle Gear Lube 75W-90
I've had the car out again for several short drives and the gear clashing is definitely gone. Seems like Passon got some bad advice from Lucas about what type of oil to use. Based on my research and experience - do NOT use a GL5 oil in the tranny. GL5 oils have friction additives specifically meant for rear differentials. GL4 oils have a completely different additive package that are meant for manual tranny's.
Jim
Thanks for letting us know what works Jim. I'll have to give it a try!
 
If you have a really high HP engine, then you may need a 75w140 oil, but I’m not sure who makes it in a GL4 tranny oil
That is something to consider. I have 535 lb/ft of torque. The 855 is supposed to take 600+. I did use GL4 80w90 conventional in my 833. It is a junkyard trans that I never rebuilt and I took it down the strip at least 200 times without issue. I would think that 75w90 would be ok in the 855, but I would hate to destroy it.
 
Jamie told me i'm #21 on the list, which will be in the next run of A body trans. with a likely timetable of 8-12 months.
 
Wow! I wonder how long it will be then for a guy like me at #181 on the list? It's already been a six year wait.
 
The A833od has pretty wide splits allrightee, but if you have an automatic-type cam of 112LSA or more, it ain't all that bad. No; not hi-performance, but a few more cubes makes all the difference.
3.09-1.67-1.00-.73od and splits of .54-60-.73 Wait aren't those same splits found in the 727? Well not quite;
2.45-1.45-1.00 and splits of .59-.69 .. But the A999s have ratios of
2.74-1.54-1.00 and splits of .56-.65, and everybody loves the A999
First to third in the regular A833 is 1.4/2.66= .526 so poster jos51700 in post 202 is pretty close; .526 ain't that far away from .540
The difference is with the regular box you would probably run 3.55s ,so second gear would be 3.55x1.92=6.816, whereas with the OD box, to get a 6.816 second gear, you would run a 6.816/1.67~4.10. Then your first would be 12.67......... and you would hardly notice the wicked split. Well OK I hardly noticed it with my small-cam 367, around town and such.
Here are your road gears with the 2.66 box and 3.55s, your typical streeter combo
9.440-6.82-4.97-3.55.. and with the ODbox you might run 4.10s, for roadgears of
12.67-6.85-3.91-2.99.. So in the OD box,low is a bit low, and direct is a bit out there, but for a streeter, that 6.85 second gear will get you 60 mph@5100, and that 12.67 is a wicked launch, and that 2.99 is super nice cruiser. So that just leaves the direct gear as ugly, but you will likely wind second out to 6200/73 mph,so you won't get to direct for awhile.
That ODbox ain't all the crap some people (not alluding to anyone specific; jos) make it out to be; at least it doesn't have to be.. But yeah if you run it with 3.23s or 3.55s, and a pipey-cammed small-engine,you need to give your head a shake.
And the truth is, you can run that box with any rear gear you want, up to ~4.88s, to get the same equivalent 3.55 hiway cruiser. But after 4.30 first gear becomes crazy-low;waaay too low for a street 360.
I ran it with 4.30s and hit 60@ ~5400 with a ~5200 peaking 110LSA, two-degree-retarded cam, in my 367; Shazaam!!
And yes, that box was terrible with the 292/508 cam and 3.55s, even with the cam advanced to 100 and at 11.3Scr. And to think I traded a mint 2.47 close ratio box straight up for it! Sheesh I was desperate.
 
Last edited:
AJ/FormS,
Would you mind doing those calculations with the ratios from the A855? 3.73 gears and a 315/35/17 tire? I think it's 25.79" diameter.
What are the Passon ratios? IIRC they are very nearly the same as the 2.66box, right? The A833 ratios are 2.66-1.92-1.40-1.00

with 3.73s the road ratios would be
9.92-7.16-5.22-3.73-2.61 (.70Passon overdrive)
with the 25.79 tall tires these get corrected to 12/12.895=.93, for a 12" radius, so
9.23-6.66-4.86-3.47-2.43. You only need to know the corrected when comparing to other combos that might be using different tire roll-outs.

With 3.73s and the .70OD, 65~2060rpm; not all cams will like this.
A 230* cam in a 360 likes 2200 to cruise, so 3.91s might be better, for a cruise of ~2160. This would also wake up the launch, and the 2-1 downshift at 30 mph, and your zero to 60 ET, if you can make it hook; 60~5870 with 3.91s.
The low-rpm cruise will want lots and lots of timing; then you can lean it out, and that's where the fuel economy starts.
 
Last edited:
Yes precisely.
2.64
1.92
1.40
1.00
0.70
I don't have the exact cam info on my 408, but it's a hydraulic roller 576/576 lift and 252/256 [email protected]. I don't remember the LSA. I could look for the dyno sheet. Just curious if my stuff is wanky.
 
-
Back
Top