Has anyone used a Gear Vendors behibd their ZF 5-Speed?

[bookite03]

Has anyone used a Gear Vendors behind their ZF 5-Speed?

I have completed my 5-speed swap into my 87 F350 in my signature, retained the GV Overdrive mounted behind the BW1356 transfer case. Basically just like it was before with the C6...
The OD operates fine behind the manual, as it did with the Auto. I only operate it in the "Manual" mode and use it for cruising over 55mph in 5th-over. Also planned on using it in 4th-over for towing conditions for some better mpg. My concern is how rough the shifting is both in and out of OD with the GV. Shifting up into OD isn't too bad, but definitely firm. However, downshifting is pretty rough. I can feel it almost "shocking" the transmission when its kicked down with the button. I pull it down while coasting in gear.
Am I doing this right or is there a better method? I don't want to destroy the GV, but I'm not ready to give up the extra low cruising rpms. Open to ideas and suggestions.

Another option is sourcing a 3-speed brownie instead

 

[racer30]

How about trying a "clutched" down shift by depressing the clutch then downshift the vender so it only has to speed up the trans not the engine. Or Shift to Neutral then downshift the vender and then shift the trans again. I would try a few ways to see what works the best.

 

[typ4]

What Brad said, also when downshifting the rpms need to increase, maybe Towcat will offer some tips, he has many miles on a GV.

 

[bookite03]

I'm going to try a few methods on my way to work, I've got a few long flat spots where I run 55-60mph. The clutch method sounds like it will help...I guess I'll know in about an hour when I'm on the road
Towcat was the first one I asked, one of his rigs in his signature has the same setup. He too had the hard shifts, wondered about the filter in the GV being clogged. Unfortunately he informed me his GV broke the case before he could move forward. Another thing is running 1600rpm at 65mph is great for fuel economy but a ways from the powerband. I think a different cam is key to making this work by moving to power curve down to the lower rpm ranges. I'm almost scared to see what kind if speeds 2k + rpm would bring in 5th-over. I'd be the "Smokey Bandit" lol

 

[hce]

I've found that downshifting with throttle applied is pretty smooth, not floored but keeping pressure on the forward side of the gears. Upshifting is the tricky one. It needs to timed with the lifting of the throttle so the engine is neither pushing or being pushed. Even when using the clutch the driveline can make one hell of a clunk when engaging.
I would also test out your 4wd lockout WITH HUBS UNLOCKED. When the gear vendors is in O.D. make sure it drops to direct when the transfer case is engaged from 2wd to 4wd. Mine keeps 4wd locked out till the key is turned off and on.
It will become habit to engage in OD, even on icy roads when in 4wd.

 

[bookite03]

I've found that downshifting with throttle applied is pretty smooth, not floored but keeping pressure on the forward side of the gears. Upshifting is the tricky one. It needs to timed with the lifting of the throttle so the engine is neither pushing or being pushed. Even when using the clutch the driveline can make one hell of a clunk when engaging.

Tried this on my way to work this morning. The up-shift into OD was very smooth, you almost can't feel it. Downshifting out if OD is also better, still have to find the sweet-spot but it doesn't feel nearly as violent which is a huge relief. Thank you for the tips!
As for using the GV in snow/ice and 4wd, we dont get nearly enough of it around here. If we did I'd just as well leave it off to be safe.

 

[hce]

At least have a master switch to disarm the system then, so pulling the shifter knob does nothing. I had the same thoughts as others that I would just be careful, would not use it with 4wd. That ended up in about a $1000 to repair the carnage to the front end. Killed the driveshaft and snapped the pinion shaft, gave me an excuse to replace the front end u-joints, and seals. The less you use 4wd, the more important it is as you fall into the habit of just shifting into overdrive.

 

[rockbender]

At least have a master switch to disarm the system .

I put in a master switch last season because I had terrible thoughts of accidentally hitting the OD switch on the floor instead of the high beams and making bad things happen (mine is behind a C6). Now I have a visual reminder and peace of mind that there is no way it can engage.

 

[bookite03]

Ouch, yes that is a must do on my list. Master switch with an indicator. Thank you

 

[hce]

I originally had my saftey wired but the 4wd indicator kept closing intermittently and hence no overdrive. In the process of troubleshooting the wire to the switch was pulled off and never replaced. After my little indecent I shimmed the switch out so it stays off is 2wd, and closes before the transfer case is in 4wd. The current gv system has no insurance if the wire from the switch to the gv units breaks, or pulled of by ice and snow. If that wire is gone it will shift. The gear vendor looks for a ground to this wire, if no ground it will shift. It is much better then nothing. I would like to add a second switch on the shifter that opens when not in 2wd, and in series with the shift solenoid. If a connection is this system failed it just would not shift into O.D. I just have to find ambition to fix something that works.

Also strength questions about a gear vendors is it is stronger then the pinion shaft on a DANA 50.

 

[towcat]

I did a master arming toggle and a push-pull switch at the shifter. the GV is now gone but the switch is still there. all it does now is satisfy a nervous tic.

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[bookite03]

I'd rather break almost anything else on my drive train before the GV...makes me cringe thinking about how much parts would cost to fix it in the case of a major failure.

Towcat, your PM inbox was full so I went ahead and made a thread. I thought other curious members could benefit from the info. I was thinking of mounting the "kill" switch on my shifter knob just as you did. I want mine to be a master system kill that disables the GV completely.

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[hce]

Do you have the wastegated sidewinder turbo?

 

[bookite03]

Yes I do.