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Manual transmission??

drainwerks

Newbie
Joined
Mar 21, 2015
Messages
35
Just curious what everybody's thoughts are I currently run a new process 435 it's always done a great job I want to stay with a manual transmission no doubt in my mind! what is everyone's thoughts on swapping to a more modern transmission something with better synchros and a 5-speed nothing wrong with my new process 435 it's been rebuilt it all works perfectly well I just would like to have another gear!

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Hotrodjohn

Full Member
Joined
Feb 12, 2016
Messages
264
AX15 or NV3550......both have similar ratios with overdrive in 5th.. You'll gain OD and lose that granny low.
 

sykanr0ng

Bronco Guru
Joined
Aug 11, 2014
Messages
5,363
If you want to keep a granny low I recommend the ZF5 it has 5.72 2.94 1.61 1.00 0.76 ratios.
 

thegreatjustino

Contributor
Red Head Grease Monkey
Joined
Jan 23, 2002
Messages
15,624
Loc.
Stockton, CA
Spend $3,000 on a swap for an extra gear. Never made much sense to me, but to each their own.

The lighter duty five speeds will drive more like a modern car if that's your goal. The NV4500 and ZF are still heavy duty truck transmissions and shift as such. Depending on your tire size and gear ratio, you may end up needing to re-gear in order to use the overdrive which adds to the already $3,000 upgrade cost.
 
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drainwerks

drainwerks

Newbie
Joined
Mar 21, 2015
Messages
35
Spend $3,000 on a swap for an extra gear. Never made much sense to me, but to each their own.

The lighter duty five speeds will drive more like a modern car if that's your goal. The NV4500 and ZF are still heavy duty truck transmissions and shift as such. Depending on your tire size and gear ratio, you may end up needing to re-gear in order to use the overdrive which adds to the already $3,000 upgrade cost.
I run 37" tires and 4.88 gears. I like the ZF 5spd just curious about size if it?

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Crush

Contributor
Bronco Guru
Joined
May 30, 2007
Messages
3,463
Loc.
Greenbottom, WV
Dont rule out the M5OD. I have one and have done a couple others. very easy install and shifts in between a 3550 and a ZF. its a full size truck trans. Get one out of an 04 v6 f150 and then enlarge the bell housing mmounting holes for our v8 bolts. plenty of metal there to do it because its the same casting as the earlier v8 transes just tougher internals and the shifter is as far back as you can get. it will pop up in the muddle of the trans hump
 

ep67bro

Contributor
Bronco Junky
Joined
Aug 28, 2008
Messages
3,642
Loc.
Easton, MD
I would be afraid of the AX15. I know a lot of people have done that swap but I know a bunch of people that had them in Jeeps with big tires and they didn't last. With the power of the V8 and the large tires you have if you wheel it hard it may not hold up. I know the ZF is a good trans and can handle a beating. Had a buddy that had one in a F250 that had over 300,000 miles on it and never had a problem. He towed and beat on that truck hard!
 

661buster1963

Full Member
Joined
Feb 18, 2009
Messages
287
I have looked at the ZF as an option too, if money were no object it would be a rather great choice, the 3000$ bogey is a deal breaker for me. Also hard to think of 4.88 gears as 'too high' but with a 37" tire you run and assume it has a 36" true diameter and the OD gear at 0.76 you will end up going 65 mph in OD at an engine speed of 2251 rpm. Others may have better opinions than mind but that could potentially be too low of an rpm for a stock 302 to pull very hard. If you like a white knuckle drive you could ease it up to 75 mph and turn a motor at 2600 rpm. A gear change to 5.13 will help , but not a huge improvement. I too have 4.88 and plan on 35" tires that might measure 34" in reality and that 0.76 OD doesn't put my 65 mph engine speed much better. At the end of the day if you cant fully use the OD then that NP435 is pretty indestructible. Depends on how much high way running you anticipate. the ZF can be found to bolt to a sbf, just adapt to tcase of choice
 

bowhunter

Bronco Guru
Joined
Apr 9, 2005
Messages
1,531
NV3550 is right up there in the best of the “mods” category for me. Love mine.
 

Nevadasmith

Full Member
Joined
Apr 30, 2016
Messages
182
Loc.
Fallon, Nv
Ok I'm not sure how the $3k figure gets attached to the zf5,
Junk yard zf5$125
Bc bronco's adapter and cross member full kit $760(you can do this slightly cheaper re using more jy parts)
Junk yard drive shafts $80 (Jeep GC front works perfectly, for the front with my i6) had to shorten one for the rear.
New pressure plate and clutch disk $140 ( this is optional)
All in a touch over $1k
I did regear but I found 5.42/5.38 sets at a swap meet for $150 and bought eBay install kits for $150
So like $1300 with regear....
I think the $3000 is the ax15, and nv 3500-4500 transmissions because you need adapters for both ends.

I love the zf5, I do wish it shifted faster, but it's totally worth it for the low first and steep OD....ps 4.88 gears would have been a better choice for 35" tires...or 37" tires would have been a better choice for 5.42 gears. But it works!
 
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drainwerks

drainwerks

Newbie
Joined
Mar 21, 2015
Messages
35
I would be afraid of the AX15. I know a lot of people have done that swap but I know a bunch of people that had them in Jeeps with big tires and they didn't last. With the power of the V8 and the large tires you have if you wheel it hard it may not hold up. I know the ZF is a good trans and can handle a beating. Had a buddy that had one in a F250 that had over 300,000 miles on it and never had a problem. He towed and beat on that truck hard!
The ZF is maybe the way I'm going

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Nevadasmith

Full Member
Joined
Apr 30, 2016
Messages
182
Loc.
Fallon, Nv
If you find an np205 tcase it fits in the frame and bolts up to the zf5/m5odr2 no adapter, but it's heavy, and has less gear reduction than the d20. And I don't know if it works with the bc bronco's cross member?
Good luck!
 

Bitch'nBronco

Contributor
Loose Cannon
Joined
Dec 1, 2005
Messages
3,348
Loc.
Havre De Grace, MD
Pretty happy with my ZF. I did it for around $1500

Junkyard ZF $100

NP205 $40

JB fab trans and NP205 shifters $260

Clutch M/C and hydraulic line $80

Lengthen/shorten/balance both drive shafts $200

Bronco hut shorty headers: $299

BC Broncos cross member: $136

Exhaust: $380
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sykanr0ng

Bronco Guru
Joined
Aug 11, 2014
Messages
5,363
I run 37" tires and 4.88 gears. I like the ZF 5spd just curious about size if it?

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It is the transmission in post #17

Not ginormous, but bigger than the weaker transmissions favored for street only Broncos.
 

blubuckaroo

Grease Monkey
Joined
Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
It is the transmission in post #17

Not ginormous, but bigger than the weaker transmissions favored for street only Broncos.

I wasn't trying to be critical of the ZF. It would be my choice if I were driving a distance to the trailhead un-trailered.
These days most Broncos don't even see a dirt road and wouldn't miss the front driveline at all.
All I'm saying is there isn't much use for an overdrive tranny with compound low gears.
 
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