Page 9 of 9
Re: Project Downward Spiral
Posted: Sat Sep 24, 2022 5:31 pm
by phyler
Well, it's been a year (almost) and I've done nothing but drive it. Got it to Super Celebration and on the way back developed a pretty rough vibration at any speed over 50mph. That made for a longer than desired drive back (3+ hours).
Got under to measure the pinion angle for good measure since I never did it after replacing the suspension. When I pulled the drive shaft to measure up against the yolk, one of the u-joint caps just fell off. Needles completely gone and the cap was cracked. Guess I found the source. [emoji16]
Pinion angle is currently at 10 degrees. Will probably buy some of the 6 degree shims to get it between 4 and 6 degrees.
The downward spiral here is that I will probably go ahead and start the transmission swap as I know I will need to modify the drive shafts. I have 95% of the parts for the ZF swap so, why not? [emoji1787]
So, who has a good transmission jack that I can borrow?
Sent from my Pixel 5 using Tapatalk
Re: Project Downward Spiral
Posted: Sat Sep 24, 2022 5:45 pm
by Eck
ThatΓÇÖs good you found the issue and I agree with your solution. The angle will only get more extreme with the ZF5 and shorter rear shaft. I was blowing through u joints too until I added shims to solve the angles. HavenΓÇÖt had an issue since adding the shims.
I do not have a trans Jack but will take the opportunity to take a dig at the HF one. It sucks.
Sent from my iPhone using Tapatalk
Re: Project Downward Spiral
Posted: Sat Sep 24, 2022 8:24 pm
by phyler
Eck wrote:ThatΓÇÖs good you found the issue and I agree with your solution. The angle will only get more extreme with the ZF5 and shorter rear shaft. I was blowing through u joints too until I added shims to solve the angles. HavenΓÇÖt had an issue since adding the shims.
I do not have a trans Jack but will take the opportunity to take a dig at the HF one. It sucks.
Sent from my iPhone using Tapatalk
Maybe I'll wait on the shims then and see if I just want to replace the perches and set the angle correctly.
In regards to the HF jack, are you taking about the crappy $50 scissor style one? Or the hydraulic one?
It's more about getting the NP435 out with the transfer case attached. It's just a lot of weight that is super awkward.
Sent from my Pixel 5 using Tapatalk
Re: Project Downward Spiral
Posted: Sat Sep 24, 2022 8:36 pm
by Eck
The hydraulic one. ItΓÇÖs more about the stability of the platform. If you end up using that one, IΓÇÖd definitely figure out a way to create a more secure base to drop the trans onto.
IΓÇÖd maybe suggest figuring out the expected perch location with weight. I tried to rotate and do mine without the weight on the axle and was off enough to have to add the shims.
Sent from my iPhone using Tapatalk
Re: Project Downward Spiral
Posted: Sun Oct 16, 2022 8:16 pm
by Kinder
Still need a trans jack? I have the larger hydraulic jack and youΓÇÖre welcome to borrow it. IΓÇÖd recommend taking the D20 out first, then drop the trans. ItΓÇÖs a bit unwieldy to drop them together.
Re: Project Downward Spiral
Posted: Sun Oct 16, 2022 8:21 pm
by phyler
Kinder wrote:Still need a trans jack? I have the larger hydraulic jack and youΓÇÖre welcome to borrow it. IΓÇÖd recommend taking the D20 out first, then drop the trans. ItΓÇÖs a bit unwieldy to drop them together.
Yes! Happy to coordinate with you.
I've done the np435 with the 20 attached more times than I'd like to count. Will definitely do them separately this time.
Sent from my Pixel 5 using Tapatalk
Re: Project Downward Spiral
Posted: Sun Nov 13, 2022 4:07 pm
by phyler
Re: Project Downward Spiral
Posted: Sun Nov 13, 2022 4:34 pm
by Eck
The BC part is the hose for the master to slave cylinder.
Sent from my iPhone using Tapatalk
Re: Project Downward Spiral
Posted: Sun Nov 13, 2022 4:57 pm
by Gunnibronco
phyler wrote:Just checking, on the ZF swap, is there anything besides the adapter that is vendor specific? I feel like in the past there was a part from BC Broncos that people recommended but can't remember what it was. I have the following parts:
Transmission
Adaptor
Need to purchase:
Twin stick
Master/Slave for a 97 F250
I know I need to fab up the piece for the clutch pedal to the master as well as I will need to fab the cross-member. After it is in, I'll need new drive shafts.
While it is all out, I will be re-sealing the Dana 20 (it works great, just has some minor leaks and why not, this is the downward spiral after all).
What else am I forgetting?
You are running a body lift? Without it, you'll really struggle to get the ZF to fit. Also expect to modify the shifter to clear the dash board. The second post on the link below seems to be the easiest way to move the shifter to a better location.
https://classicbroncos.com/forums/threa ... 977/page-2Buy the best master and slave you can. You don't need to bother buying a kit with the line from the master to the slave cylinder. It won't fit and you'll need the soft stainless line BC offers. I built an adjustable pedal stop into my clutch pedal. I've read that you can blow the seals out of the slave cylinder if your pedal travels too far. I can't confirm this and I'm not sure how real the problem is.
But pulling the trans to replace the slave cylinder is something you'll obviously want to avoid.
Re: Project Downward Spiral
Posted: Sun Nov 13, 2022 5:55 pm
by phyler
Gunnibronco wrote:phyler wrote:Just checking, on the ZF swap, is there anything besides the adapter that is vendor specific? I feel like in the past there was a part from BC Broncos that people recommended but can't remember what it was. I have the following parts:
Transmission
Adaptor
Need to purchase:
Twin stick
Master/Slave for a 97 F250
I know I need to fab up the piece for the clutch pedal to the master as well as I will need to fab the cross-member. After it is in, I'll need new drive shafts.
While it is all out, I will be re-sealing the Dana 20 (it works great, just has some minor leaks and why not, this is the downward spiral after all).
What else am I forgetting?
You are running a body lift? Without it, you'll really struggle to get the ZF to fit. Also expect to modify the shifter to clear the dash board. The second post on the link below seems to be the easiest way to move the shifter to a better location.
https://classicbroncos.com/forums/threa ... 977/page-2Buy the best master and slave you can. You don't need to bother buying a kit with the line from the master to the slave cylinder. It won't fit and you'll need the soft stainless line BC offers. I built an adjustable pedal stop into my clutch pedal. I've read that you can blow the seals out of the slave cylinder if your pedal travels too far. I can't confirm this and I'm not sure how real the problem is.
But pulling the trans to replace the slave cylinder is something you'll obviously want to avoid.
Thanks. I am running a body lift.
Ok, I'll look for the line on BC's site. I didn't see it last time I looked but that site isn't the best.
I'll look for the master and slave as separate parts vs the kit then.
Sent from my Pixel 5 using Tapatalk
Re: Project Downward Spiral
Posted: Sun Nov 13, 2022 8:38 pm
by Gunnibronco
Yeah it's pretty bad I just checked it out. I was able to search "zf hose" and find more than using their product catagories. You may be able to have a local hydraulic shop make the line instead of using BCB. They aren't my favorite vendor.
Sent from my E6910 using Tapatalk
Re: Project Downward Spiral
Posted: Wed Nov 23, 2022 7:42 pm
by phyler
Ordered on Sunday night. Both BC and rock auto showed today. Jb fab twin stick should be here on Friday. Guess I need to make this happen.

Sent from my Pixel 5 using Tapatalk
Re: Project Downward Spiral
Posted: Sat Mar 04, 2023 6:12 pm
by phyler
Well, the old NP435 is out.

Now I need to get the Dana 20 cleaned up and resealed. How hard is it to do?
Anyone need an NP435 with adapter?
Re: Project Downward Spiral
Posted: Mon Mar 06, 2023 2:23 pm
by Kinder
Sealing the D20 is easy, grab a couple of output seals, front & rear, and a PTO cover seal and your done. Check the yokes for wear where the seals sit, if they are bad you may want to get replacements or theyΓÇÖll continue to leak.
Re: Project Downward Spiral
Posted: Mon Mar 06, 2023 5:55 pm
by phyler
Kinder wrote:Sealing the D20 is easy, grab a couple of output seals, front & rear, and a PTO cover seal and your done. Check the yokes for wear where the seals sit, if they are bad you may want to get replacements or theyΓÇÖll continue to leak.
Sounds easy enough. Just need to clean this sucker off.
Sent from my KFKAWI using Tapatalk
Re: Project Downward Spiral
Posted: Sun Sep 17, 2023 7:21 pm
by phyler
Felt like I should do an update. The ZF project is taking forever due to my travel schedule. We got the transmission in back on Memorial Day weekend. Got the cross member finished in August. This weekend, I got the master cylinder in and modified the clutch pedal.
Sadly, it appears the slave is bad. I know @Eck ran in to this. Have been trying to bleed it for hours and no change in pressure. So, transmission gets to come back or. [emoji2959]
I had bought Luk for both the master and slave thinking it might be better. Evidently, that doesn't matter as pretty much all of them have the same reviews.
I'm back on the road for the next two weekends so it will have to wait again. Might try and get the measurements for the driveshafts so I can get those going. Maybe if they come in, I can do another wrench day to try and get it all going in one shot.


Sent from my Pixel 5 using Tapatalk
Re: Project Downward Spiral
Posted: Sun Sep 17, 2023 8:14 pm
by Justin
If it makes feel any better you're still going faster than I would. I spent the extra for a Sachs master and slave because of Eck's experience and had no issues with bleeding.
Re: Project Downward Spiral
Posted: Sun Sep 17, 2023 8:37 pm
by phyler
Justin wrote:If it makes feel any better you're still going faster than I would. I spent the extra for a Sachs master and slave because of Eck's experience and had no issues with bleeding.
Good to know on the Sachs. I really thought Luk would make a decent setup.
I hope to have it done before the end of the year. [emoji1787]
Sent from my Pixel 5 using Tapatalk
Re: Project Downward Spiral
Posted: Sun Sep 17, 2023 8:48 pm
by phyler
Looking online, it doesn't show that the Sachs fits. My ZF is out of a 97 F250. It's the 47 and not the 42 version.
Wonder what is different between them.
Sent from my Pixel 5 using Tapatalk
Re: Project Downward Spiral
Posted: Sun Sep 17, 2023 10:03 pm
by Justin
No idea, but mine is a 42
Re: Project Downward Spiral
Posted: Mon Sep 18, 2023 7:24 am
by phyler
What's more interesting is the Luk part is the same for 96 and 97. Guessing that 97 is just a bit of an odd ball as it was the end of the line for that transmission in the trucks. Probably no difference. Rock Auto has the Sachs for half the price of the local stores. Might have to try it.
Sent from my Pixel 5 using Tapatalk
Re: Project Downward Spiral
Posted: Sun Sep 13, 2026 3:09 pm
by phyler
Well, I have pretty much just been driving mine since @Kinder helped me get the transmission going.
Given the circumstances, I decided to take advantage of a fully free Saturday and get the 23 gallon fuel tank that I got from Tim (@BroncoRaider ) two years ago. I've been stepping over it to get to my workbench so it was time.
Not too bad a job. It was a 4 out of 10 on the difficulty scale simply because I did it by myself. I also introduced myself to a new tool with Deutsch connectors for the sending unit.