I have a 1994 full size Bronco with the 5.8L and the ZF 5-speed manual transmission for the F450’s & F550’s, that I acquired new from Jasper Engines a few years back. Suffice to say that I would not take offered money to install another ZF in any of my trucks. It is a noisy, over-engineered, German piece of junk that I would advise all to stay clear of. Granted this is my opinion and there are likely other gear heads that may not agree, but I installed the thing new from the manufacture via Jasper and have been driving it for the last few years with much disappointment having always thought I should have spent the money on a NV4500 solution. Now it is making enough rude noises to give any gear head with the strongest stomach a little indigestion at a suggestion of a twenty mile trek in my truck. So, I am going to do what I should have done in the beginning and go with the NV4500.

OK, has anyone done this swap for the final years Bronco? Bronco Graveyard has an adapter kit (ITEM #31550), has anyone used this kit? It requires a Ford bell-housing with the 4.848” index diameter, but what do I do about my hydraulic clutch system? None the less, I have to make the hydraulic clutch system work. Also in the kit is an adapter for mating the NV4500 to the Borg Warner 1356 transfercase. Any constructive comments or suggestions are very welcomed and appreciated. Also, a few resources for reliable and affordable NV4500 transmissions would be great.
Thanks for the help, -blake

 

Welcome to Ford Truck Enthusiasts.

The gear rollover in the low gears is a little annoying in the ZF's, but other than that you shouldn't really hear too much. What fluid do you run in the tranny? A good synthetic ATF generally will quiet them down. Might also be a clutch issue or maybe that big ole case is rubbing the frame or body somewhere.

I can't really help you with the Dodge transmission....I don't know much about them.

 

Cookie88, thank you for your suggestions. I have tried a few different fluids from cheep fossil to expensive synthetics, no change. The case has plenty of room and the noise from the trans is gear related, not rubbing or tapping from collisions with the case. I have also changed out the entire clutch system, throw out bearing, and pilot bearing, still no joy.

The noise is most prevalent in fourth and fifth gear at 50MPH and above, particularly if the drive train is not under load (i.e. when cresting the top of a hill or in the valley of a road where the engine is, though briefly as in coasting, not propelling the truck or dragging it down as in a downshift deceleration). This ZF trans in my Bronco is a heavier duty version than was ever installed by Ford in the F250s & F350s. It was installed in F450s & F550s. I figured if it was made for those trucks, I was bound to have a heavy duty enough transmission for my 4x4 Bronco. My bad for using logic…

I did not really like the ZF five speed from day one, and I had an earlier unit that I rebuilt myself, but had noise. So I got a replacement that was brand new from ZF via Jasper Engines, and it had the same d@mn noise. None the less, no longer am I concerned with the ZF. We are going to sever our relationship and go our own separate ways. It to the ***** pile, and I on to a tried and true NV4500 – which brings me back to previous post where all those questions still apply…

 

Wow.... that is very interesting...

I installed a used ZF a while back... maybe 2 years ago... it had a mild input bearing noise, but nothing like the noise you speak of... A month back the input bearing finally started making all kinds of noise and now it is time to deal with it...

I just helped my buddy put one in his K5 Blazer. After all the work it is loud as all heck and he had to take the truck off the road as it was SOO bad he could not drive it... looking at rebuilding was also $$$$$

Advanced adaptors has what you need if I remember correctly... I cant remember if they have a kit for internal slave or not, but they do offer the adaptors for small block fords....

Good luck, I would love to know how this turns out for you!! are you planning on running a dodge unit? or an early chev or late chev unit?

 

Hey there Mr. Bob, I do not know what exactly is the difference from the 5 spd ZF model that was installed in the F250/350’s versus the model installed in the F450/550’s but there is a difference since my model for the F450/550’s can take more torque. And when I ordered the rebuild kit for my model of ZF if was not the same kit as would be used in the F250/350 ZF. Perhaps the subtle difference has resulted in the not so subtle noise difference. Please keep in mind I have history with two different transmission of this same F450/550 ZF model in my Bronco. Both made the same noises.

Bob, unless you are gifted with transmission mechanics, I might recommend that you have a tranny shop work on your ZF. I have Ford’s manufacture manuals for all light duty trucks and Bronco for ’94 which covers the F250/350 ZF and it was helpful for when I rebuilt my first ZF trans. Even with the detailed instructions, the ZF 5spd is no walk in the park. The Germans way over engineered this transmission. You need gauge blocks, jigs, holding frames, and such to work on this thing. I improvised everything and it took me days to put the d@mn thing back together. I had to finally use wire, zip ties, and welding rod to hold the overly complicated assembly together long enough to get the case back on. So if you are going to take on that challenge, I wish the best to you. After the rebuild, my ZF made noise, so I figured I really messed it up somewhere in the rebuild process and cut my losses (so I thought) and ordered a unit from Jasper. The new unit made the same noises! Talk about PO’d.

Anyway, I plan on using Bronco Graveyard’s #31550 adapter kit: http://broncograveyard.com/bronco/i-31550_nv4500_trans_kit__does_not_include_transmiss ion_.htm It requires the Doge 4x4 NV4500 with the 29 spline output shaft. I have a late ‘80s Ford 300 I-6 bell housing coming. Apparently ’85 to whenever Ford started using transmissions that have an incorporated bell housing, those detached bell housings utilize hydraulic clutches, so it should hopefully work with my ‘94’s stock setup. I will have to make the hydraulic work one way or another. Time will tell…