Four Speed top loader in Bronco?

[Ranchtruck]

it take more torque to run in OD than it does in 1-1.

Not if the gear ratios are lowered to take advantage of the OD. In the numbers I put out, the 170 would actually be spinning a bit faster in OD with 5.43's than in 1:1 with 4.11's at the same speed. That's the point, you get much lower gearing in the axles, which helps the lower end, but don't sacrifice the same cruising speed to do it.

 

[Explorer]

Explain to me how it's going to use a 2.78 first in a toploader better than the stock 3 speed 3.41 first? Stock 3spd with 4.11's gives a 14:1 first reduction. Toploader gives a 11.4 first reduction, which you need a torquey engine to be able to pull off without smoking the clutch all the time.

The point of an OD is not faster highway speeds. It's being able to run really low gears in the axles without loosing highway speed.

So he could run 5.38/5.43's with the OD, which would work out to a 17.85 first gear reduction, and in OD be the equivalent of having 4.39's with the stock top gear. That's a decent improvement without loosing highway speed.

Now run the 2.5:1 low range into that, and you have a 44.6:1 crawl instead of the stock 35:1 crawl.

Which engine are you talking about? His isn't going to do well with the OD or the wide ratio. Better off with his 3 speed. Main complaint of six cyl owners is engine screaming and top speed of 55 mph. Mine would handle a 2.78 first gear and the 1.35 third gear would be handy. But we're not talking about my vehicle.

 

[broncnaz]

Not if the gear ratios are lowered to take advantage of the OD. In the numbers I put out, the 170 would actually be spinning a bit faster in OD with 5.43's than in 1:1 with 4.11's at the same speed. That's the point, you get much lower gearing in the axles, which helps the lower end, but don't sacrifice the same cruising speed to do it.

In that case all you've done is improved low end and only maintained top end so you've dumped a lot of money into very little gain. most people dont want to dump that kind of money and work into a vehicle and see little gain and few will swap axle gearing just to gain a lower craw ratio. your better off swapping in a transmission with lower gearing in that case.
I'm not disagreeing with you as the basic concept is there but when your running one of the small 6 cyl engines or really any engine you have to account for the engines powerband to get the RPM's where it needs to be thats where your swap attains its gains. Again main issue with the 170 is it just doesnt have the torque to keep the bronco happily moving in OD.

 

[red hot71]

I owned one of these trannies in a v-8 bronco that the po installed a week after he bought it new in 73,at first I though it would be a neat option but as said earlier it was laking a good first gear and you were always shifting it,I mean it never seamed be in the right gear,but it had a great passing gear.The conclusion I came to was it might be ideal in a superlite weight high horsepower proper geared sand drag type machine,but there again I think a good automatic would beat it 3 out of 4 times.

 

[Quick & Dirty]

The issue I have with the overdrive toploaders is the big ratio jump from 2nd to 3rd. It's worse than 3-4 on the NP435, which sucks on my F250 with a big block. Can't keep it in the powerband.

 

[bad 68]

I ran a 4sp top loader behind a decent 351w. Off road I hated the high first gear and reverse is even worse. On road it was awesome. First was great for highway use and the third gear for passing and cruising below 35mph was used more than any other gear.
The 4spd top loader Will NOt handle a 460 period! Ford only offered the OD top loader( aluminum case and built by Tremec) behind 300 sixes F150 and 302 broncos. I swapped out the 10bolt top loader for the TremecOD. It had nearly identical gear ratios as the original 3sp with an OD.
The Top loader with a Hurst shifter is the smoothest, fastest shifting 4sp you will EVER drive. I am 43 and have driven a lot of newer 4, 5 and 6 speeds and nothing shifts smoother or faster. If you only dirve the Bronco On Road go with the 10bolt.

 

[Quick & Dirty]

The 4spd top loader Will NOt handle a 460 period!

Ford put the big input close ratio trans behind 429's. Those will handle plenty of torque.

People run them behind 460's, so I don't think the strength was reduced any when they swapped 3rd for an overdrive.

First gear is quite a bit lower on the OD units. More gear multiplication allows for less torque input. From the factory, 390 and larger engines got the 1-3/8" input, 2.32 first gear trans.

 

[Ranchtruck]

In that case all you've done is improved low end and only maintained top end so you've dumped a lot of money into very little gain. most people dont want to dump that kind of money and work into a vehicle and see little gain and few will swap axle gearing just to gain a lower craw ratio. your better off swapping in a transmission with lower gearing in that case.

Which is why a ZF, np435, or even the stock 6cyl 3speed makes more sense than any toploader. I'm not recommending a toploader, but if the OP is set on one, the OD one will at least match the capabilities of his existing 3 speed and offer improved capabilities over it if he regears the axles to take advantage of the overdrive.

 

[Boss351]

here's one combo toploader with t176 ,t177,t178 gears in it 3:52,3:82 3:01 first the jeep gears swap in

 

[broncnaz]

Which is why a ZF, np435, or even the stock 6cyl 3speed makes more sense than any toploader. I'm not recommending a toploader, but if the OP is set on one, the OD one will at least match the capabilities of his existing 3 speed and offer improved capabilities over it if he regears the axles to take advantage of the overdrive.

Well if you read the OP's post he was asking about a 66 toploader out of a mustang not a OD. Someone else brang up that the OD version has the lower first gear still does nothing for him unless he changes axle gearing which I highly doubt he wants to do. And a ZF wont bolt to a 170. So your way out in left field on that one.

 

[Ranchtruck]

A 2.78 ratio first and a 2.8l engine is not a good combination. He's going to need to ride the clutch to get the thing moving, it'll power out and stall trying to climb anything steep at low speeds, and it's going to have the exact same top speed. It makes no sense to put in a transmission that neuters the trucks performance.

The smaller the engine, the lower the gearing you need to make it drivable. He needs a deeper first, or deeper axle gearing to help that engine move the truck. Putting in a Mustang Toploader does exactly opposite of that. Same top gear, but now with a sucky first. Talk about putting in a lot of effort swapping and not seeing much result.

 

[broncnaz]

I agree and thats what we were telling him before someone even brought up the OD version. It just show you how easily things get off track when people try and offer alternate solutions to the OP's original question instead of just answering the basic question. When he was only asking because he has a part already not because he wants to go find another part and swap axle gearing

 

[GrillMaster]

I have a wide ratio toploader in mine behind a 4V 315C and I can say it shifts great (hurst) and it would be ideal for a mostly street driven bronco. I am rebuilding mine now and will use it for a a bit while I look for a nice used ZF to swap in. I'm building mine as a mild rock crawler and I could use the extra low and top end of the ZF with my 35's and 4.11s. I have no clue how it would work with a straight 6.

If I were you I would swap 302/351W and a ZF in and be done with it. But thats just me.

I'll be selling mine rebuilt in the next year if anyone is interested PM me. Or I may have to convert it back to 2WD and throw it in my 64 Fairlane.

 

[Ranchtruck]

I have a wide ratio toploader in mine behind a 4V 315C and I can say it shifts great (hurst) and it would be ideal for a mostly street driven bronco.

I have no clue how it would work with a straight 6.

Little bit of a difference between a performance 5.8l and an economy 2.8l. It's literally more than twice the engine, so the 6 has less than half the bottom end power to get the same truck moving.

 

[GrillMaster]

Little bit of a difference between a performance 5.8l and an economy 2.8l. It's literally more than twice the engine, so the 6 has less than half the bottom end power to get the same truck moving.

Unfortunatley my motor is not set up for bottom end but I agree it is a lot more motor then the 2.8. Mine starts building power at about 2200.

I must say the toploader has gotten me up some tough trails but with this gear and motor setup I need to gas it up the rocks and its rough on the clutch at times, I do much better in the desert n dunes with the RPMs and speed up.

I think ZF and some 3V aussie heads are going to be ideal for me because I like to go everywhere.

 

[broncnaz]

I hated the toploader offroad for anything other than fireroads in the rough stuff you had to be in 4lo and still wasnt good. drove with the toploader for many years behind my 302 worked well on the street just didnt like it offroad went to the NP435 and was very happy now the toploader sits in my shed next to the C4 and ZF. I'd do the ZF but really dont want to change axle gearing at this point.

 

[GrillMaster]

Wouldent 4.11s and 33s work well with the ZF?

"I'd do the ZF but really dont want to change axle gearing at this point."

 

[broncnaz]

Not really with a 302 a 351 maybe but still if your in OD at anything below 65 mph you may not have the power to maintain speed at that RPM in OD. OD takes more torque to keep turning than 1-1 gearing. Most people suggest going with 4.56 or 4.88 gears when running 33's with OD. Of course if your engine is biult for nothing but lowend torque then it will be fine. but a C motor likes to rev I cant see limiting it with a low RPM cam be quite a waste of a motor with the heads it has.

 

[bad 68]

The issue I have with the overdrive toploaders is the big ratio jump from 2nd to 3rd. It's worse than 3-4 on the NP435, which sucks on my F250 with a big block. Can't keep it in the powerband.

My typo was that the Top Loader wouldn't handle a big block. I meant to say that the Tremec OD would never handle 400Ft lbs.
I took the cluster gear bearing surfaces off of a 4 spd OD with only about 375 ft lbs in about 2500 miles. And yes it had proper oil.
I agree that the jump between 2nd and 3rd on the 4spOD is horrible.
I agree that a SIX doesn't need 2 axle gear swaps and a tranny swap. Not cost effective. A 3550 would make more sense.
If it is only going to be highway driven than yes 4spd Top Loader with 4;11 and 31inch tires behind the SIX would be OK.

 

[TBS-POPS]

I had a TL 4spd in mine when I bought it. great street trans, if it was a MUSTANG so out it came for a 435. still have it, the tl 4spd with d20 adp, 4 sale $500.