Gear vendors overdrive in Travelall

[74travelall]

I am about to pull the trigger on ordering a Gear Vendors overdrive but wanted to check to see if I am missing something regarding fitment as they do not make one specifically for IH. Some details:

- 1974 Travelall 100 2wd
- 727 with a 18.5” tail housing
- I was going to order the 727 truck/towing 2wd overdrive listed to replace an 18.5” tail housing with a slip yoke and no parking brake

I have read that there might be differences in the output shaft diameter where the tailhousing bushing or bearing sits on the Travelalls and trucks compared to non-IH applications but was not sure if that is true and if so did it apply to the 2wd version?

I am trying to ensure that I am aware of any potential issues prior to placing the order. Does anybody have experience installing a gear vendors overdrive in a Travelall with a 727? Thanks

 

[MrKenmore]

Should be interesting Brad. Good luck! What gears do you have out back?

 

[74travelall]

3.07. Pretty good already but on the highway at 75 or so keeping pace with most traffic I am just under 3k RPM. I would like to drop that down as I spend a ton of my time on the highway. I don’t think it will be over geared given the torque curve of these engines but I will find out. At least with this overdrive I can control it manually or put in auto mode where it kicks in at a set speed.

 

[C.R.Glow]

I have 3.73’s in my ’72 travelall with a 727 trans, so I’m very interested in this swap, thanks for posting

 

[MrKenmore]

OK! I am 3.54. Right in the middle of you two guys.

 

[scoutboy74]

This doesn't answer your question, but in the full size rigs, the TF727 output housing and shaft is the same for 4x2 and 4x4 due to the divorced transfer case in the 4x4 models. It is an IH specific housing and shaft though. I have no idea regarding your fitment question. What does the vendor have to say about it?

 

[mallen]

That's a pricy upgrade. I'm curious how it will work out. I so have to ask, are there any overdrive automatic options for an sv?

 

[scoutboy74]

That's a pricy upgrade. I'm curious how it will work out. I so have to ask, are there any overdrive automatic options for an sv?

GM 700R4, but that takes an adapter from Advanced Adapters. They're not cheap, plus the cost of the trans.

 

[mallen]

Seems gear vendors is it. How much space do you have between the end of the tranny and the transfer case?

 

[MrKenmore]

Not sure of pre 74/75 but I believe the tails of the TF727 were different for 2WD vs 4WD. 2WD being longer.

4WD

2WD

 

[RinTX]

That’s interesting- the different lengths. Makes you wonder why with the divorced transfer case.

 

[J.J.]

At one time, I was considering a GV unit on my '73 4x4 Travelall, it never got done. From my then research, it would have been on the back of my NP 205 and would have required a massive shortening of the rear drive shaft. The Travelall driveshaft is very short to begin with, it would have taken 15-16 inches out of it.

Perhaps the over all shortened 727 case had to do with the driveline angle, although in all the ones that I have owned I have not noticed a difference in the tail shaft. Ill have to look at what I have to see.

Also the obvious too, the front part of the case is the same for the Scout application, just again the tailshaft different to mated vs divorced.

JJ in TN

 

[Zaedster]

True 1974-75' 2WD PU/TA's used a slip yoke style rear tail housing vs fixed yoke found on the 69-75' 4x4.

That is a lot of money for that overdrive unit. You will still have to get a new driveshaft.

 

[74travelall]

Thanks for posting the pages from the parts manual. For some reason my parts manual is missing the 2wd tail housing pages. From the diagram it looks like the 2wd uses a bushing and the 4wd uses a bearing. The 4wd tailhousing in my manual shows both a bearing (28 in the diagram above) and a bushing (30) at the rear end of the tailhousing but states the bushing as NA. The 2wd with the longer tailhousing only shows the bushing. I thought the “normal” non-IH 727 used a bushing. I would love to have the dimensions (ID and OD) of that IH bushing to be able to discuss with Gear Vendors to confirm that the bushing (or bearing) in their replacement tailhousing has the same ID. Anybody know those bushing dimensions or have an output shaft handy from the longer 2wd version they can measure the diameter? I guess I could pull the tailhousing and measure the output shaft and bushing but that seems like a real pain just to put it back together to be able to drive while I am waiting on the overdrive.

 

[74travelall]

At one time, I was considering a GV unit on my '73 4x4 Travelall, it never got done. From my then research, it would have been on the back of my NP 205 and would have required a massive shortening of the rear drive shaft. The Travelall driveshaft is very short to begin with, it would have taken 15-16 inches out of it.

Perhaps the over all shortened 727 case had to do with the driveline angle, although in all the ones that I have owned I have not noticed a difference in the tail shaft. Ill have to look at what I have to see.

Also the obvious too, the front part of the case is the same for the Scout application, just again the tailshaft different to mated vs divorced.

JJ in TN

On my 74 2wd Travelall the driveshaft is one piece and is around 55” long.

 

[74travelall]

I just got off the phone with Gear Vendors and walked them though my details and questions. The tech was confident it would work with my vehicle given the details I provided. I took the plunge and ordered the overdrive. I will post here the details of the install once complete.

 

[mallen]

You might have to relocate the transfer case and have the rear drive shaft shortened. If it won't work with the tail shaft housing you have, you might be able to swap it out for one that will work.

 

[MrKenmore]

You might have to relocate the transfer case and have the rear drive shaft shortened. If it won't work with the tail shaft housing you have, you might be able to swap it out for one that will work.

It's 2WD so you don't have all those pesky 4WD problems LOL.

 

[Jesse Stewart]

I have a wonder about the 46RH Trans .. ??

 

[MrKenmore]

I have a wonder about the 46RH Trans .. ??

View attachment 207815

Interesting..............same concept.........TF727 with OD.