ZF Transmission Seals

J

jmeirhofer

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I have ZF 302 transmission in my boat. One has a drip when under way from the propeller shaft seal. I have the manual and exploded parts lists for parts. While there is nothing specific in the manual about replacing this seal, it appears to just be a pressed in seal (although there is a special tool to do it) with no other real special attributes.

Question, has anyone else ever replaced theirs? In or out of the boat? While I do have a quite a bit of room down there to do this, I am thinking it is still going to be a 3 on a 1-5 difficult scale. Would like to hear from anyone else that has done it.
 
can you post a pix of the assembly drawing?
 
on my 301 it looks like the rear plate can be removed and the seal is mounted in that.
 
It is part number (33) in this image. Obviously a v-drive so the shaft goes through the unit from that side to the other where it is bolted in. While the prop shaft is out I am also considering replacing seal (13) and o-rings (8)&(12), although they do not leak.

Untitled-1copy_zpsd8daae26.jpg
 
Give it time Dave. They will. And just a few drops make a heck of a mess.
 
I have owned my boat for about 7 years maybe it's time to move on! You told me I was going to have problems with my Porsche so I sold it. If I keep listening to you I will have no hobbies left:)

Are you sure it's your Trans? Is it 30 weight oil or is it pink? The one leak I do have is my coolant I replaced the caps on my tanks and they still leak I will order a set from Cat in case the one I replaced were wrong to begin with.

Keep us up to date as to this leak and how and if you fix it.
 
Don't see anything on account of me. I don't want to cause you to have no hobbies. A man has to have hobbies!!! But that tranny was a ticking time bomb for sure.

Yeah. It is definitely the trans. It is not bad, in fact the fluid level does not go done noticeably all season. But you would think I dumped a gallon jug on the spinning prop shaft after a couple hours running. Okay, that might be an exaggeration but it is leaking and I don't want leaks. On the other side my norcott is losing fluid out of the boat (a lot worse I might add) so I am pulling the shafts anyway to change those. I figured it would be a good idea to get this out of the way too. That is why I am thinking I should do the top seals too even though they don't leak now.
 
quote:
Originally posted by jmeirhofer

Here is a shot of the actual seal in the boat

006-1.jpg


Click to expand...


John - I'm curious about the configuration in your pic. How is the prop shaft retained tight in the ZF v-drive , as there does not appear to be a shaft to v-drive coupler?
 
It passes through the transmission and is coupled to it on the other side. I will look to see if I have a photo of it later.
 
Once the shaft is out the seal should be easy . Probably can pry it out with long screw driver and looks like keeping it properly aligned while tapping in place will be only challenge. Seals have thin metal shells.
 
Sandy - I do not have a picture of it in application on my boat but this is from the service manual

zfdrive_zps38260822.jpg
 
Try a can of transmission seal conditioner. In 75+% of the cases it will do the job for 3 to 5 years.
 
I have to pull the shafts to replace the norcott seal anyway. Might as well fix it right since the shafts are out. I plan to be out of the water for April and May. While I have a laundry list of things to do, the main reason was to remove all of the old bottom paint, check/repair any blistering I find, reapply a barrier coat and fresh bottom paint. Since I will be doing all this myself and the boat is out anyway, I figured good time to replace my leaking norcott seal. Since I was doing that I decided to do the leaky trans seal and replace the strut bushings. I was going to send out the props and shafts for a tune up as well. It looks like I will also be removing my rudders and rehabbing them as well.
 
So I went to the boat today to make sure the 2' of snow hadn't caved in anything and all was good. Thought I would take a couple of additional pictures while I was there of the seal debacle.

Stuck my phone down under and took this one. While looking at it full screen a bit ago I noticed it appears the seal is not fully seated. I am going to have to look closer at at that when I go back. If it is not fully seated, I may try to tap it in place before heading off to the haul out.
5C47B0ED-D2A5-4410-AA11-24C8726F0937_zpslxgdxfl7.jpg


Stuck my arm around the back side and took this picture. It is the coupler where the shaft exits the transmission. Obviously need to get in there and clean that up and get some paint on that. But this gives you the idea of what I am looking at.
0FB47B65-41CD-42C5-821D-A29B12DA034C_zpsfizspggn.jpg

F4608129-E18E-4485-AE0C-DE7D3A6729B1_zpsozunculs.jpg
 
As I said I am not familiar with v drives but looking at the pix several questions arise.

It looks like I can see up along the shaft so the shaft is not what the seal rubs against. Instead it looks like the tube that the final gear is mounted on rotates along the entire length and that is what the seal wipes ( but where is the end bearing??). If that is true then what I see protruding may be the end of the tube not the seal. Furthermore that ring with the castellated slots may be a retainer though it doesn't show up in the drawings. If you tap in the end if it sounds soft it is likely a seal of oit sounds hard it probably in the torque tube.
 
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