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Shift Shaft Seals Procedure Clarity?

Discussion in 'Mondial' started by moysiuan, Dec 22, 2019.

  1. moysiuan

    moysiuan Formula 3
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    I am going to tackle the shift shaft seal replacement this winter on my 1988 Mondial cab 3.2. I have searched the various threads on the Mondial and 308 boards, and frankly, it is not reassuring, in that there seems to be all kinds of different ideas on how to do this. I have looked at alot of threads, maybe I am missing some but I can only conclude that this procedure seems simple for some ("a leisurely one and a half day job") to having all kinds of problems (can't get the shaft out, new seals too tight to reinstall shaft, staked nuts (but don't damage the transmission case), shifter out of alignment, etc.).

    For example, some say you remove the oil sump pan, and not the gearbox sump, but then caveat if you are using the aftermarket quad seals you do need to remove the gearbox pan. I am going to use the factory style OEM seals (bought the kit from AW Italian) and I don't understand why one would not since mine lasted 30 years and the install is less problematic? Some say you can't actually get the shift shaft out without removing the whole shifter itself with the console removal etc., others say you can and still others say you can but you have to loosen the engine mounts and slightly shift the engine (! why would anyone do that if there were other options). Some refer to removing a staked aluminum seal retaining washer, others suggest that is not required or make no mention of this. Others refer to getting the new seal in with a finger and a tool, but what tool is never described. Some refer to the one seal that leaks outside the car, little is said about the one that goes into the oil sump.

    There is a special tool in the Unobtanium catalogue to help align the shifter, looks like it holds the spring and balls in while still allowing the gearbox pan to be open. But there is no clear information on how to use this tool or why others do not seem to use it? Some say you must get this tool. Others do not seem to do that. The whole shift alignment procedure also sounds like there are different opinions on how to do it (second gear verses third gear shifter placement, eg). Some refer to an unspecified tool to stake the washer, suggesting there is not enough clearance to hammer it.

    My car shifts perfectly, and but for some oil drips I wouldn't change a thing. But if this seal is dripping, and I presume its original, the other one that connects the gear and oil sumps probably is also at the end of its life as well, so time to proactively replace before things get more serious. I am quite worried about making the shift quality worse, whether I do the work myself or get the very scarce mechanics in my small Toronto market to do the job.

    Can somone point to or clarify a procedure that is specific to the Mondial (rather than the 308, maybe that is why there are different approaches in the threads?), and provide some fresh advice on the tools/parts required, at the least I want to have everything I need on hand before I start into things. The main events for me are: do I need to remove the oil sump...do I need to remove the console and shifter...tool to insert new seals...shift alignment procedure using Unobtanium tool.

    I had success renewing the differential seals last winter, and the procedures were clear, the recommended Hill Engineering seal insertion tool was very helpful, and I had no surprises (other than how messy it gets to clean out a CV joint).
     
  2. yelcab

    yelcab F1 Veteran
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    Well, who's you gonna believe?
     
  3. Wade

    Wade Two Time F1 World Champ
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    Do it yourself for the fun, challenge, and satisfaction. I thoroughly enjoyed every second while doing mine. Otherwise, hire someone who's done it before. :)

    About the "tool", it greatly simplifies adjusting/aligning the shift mechanisms. Mine was perfect afterwards.
     
  4. moysiuan

    moysiuan Formula 3
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    Thank you, I enjoy the challenge as well, and also understanding how the whole mechanisms work, it really is mechanical art the way I see it.

    It seems to me that each thread is explaining slightly different procedures, ie. some are replacing all the shift linkage silent blocks as well, others just the seals, albeit the whole thing with the staked aluminum washer I don't understand, and does not seem part of most procedures.
     
  5. Rifledriver

    Rifledriver Two Time F1 World Champ

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    Never done more than remove trans pan and rear portion of shaft only. No need to make the job hard or bigger than it is. Also never used factory tool for adjusting shifter. Always thought it was a crutch for the lazy guys at the factory and led to many iffy adjustments. Gets it close and dumb luck is at play if its any better than that using their method. Eyeballing it with the pan off is a far more certain way to get it right.


    Never ever remove the staked washer. Thats a really dumb move.
     
  6. yelcab

    yelcab F1 Veteran
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    Because you don't need to remove the staked aluminum washer. You just need to reach in with a pick tool and remove the rubber oring (not a seal), and replace it with the same oring. Even the quad seal is just a quad oring.

    As for alignment and removal of the shaft, it is slightly different from one car to the next. Some have enough clearance to get the shaft out, some need to have its engine mounts loosened and turned slightly to allow the shaft to come out. Your car may be easy or not.

    Some people go in there just for the minimum (the orings), while others go in to replace all linkages and bushings as preventive maintenance. You can choose which camp to belong.
     
  7. moysiuan

    moysiuan Formula 3
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    Great help, thanks. That's the type of clarifications I was hoping for. Also explains why some people are talking about the shaft removal as difficult and others not, one might have expected a difference perhaps in the 308 verses Mondial, but not on the same car, I guess motor mounts settle differently and clearances are tight. This is immensely helpful to know, in that if in the process of my project I couldn't get the shaft out I would have thought I was doing something wrong.

    The Rifledriver approach is obviously most appealing with the trans pan removal only. I am curious why would anyone remove the oil pan if that is not needed, eg. I recall three threads that say remove the oil pan, with all the attendant hassle of the oil di[pstick causing lots of frustration. Is the oil level in the sump below the shaft level, I presume I don't need to drain the oil to not have it coing out while removing the o ring? Do people just do this to put fresh gaskets on the sump while under there? I might well do that.

    I presume the Verrel tool for the shift shaft adjustment just puts the spring tensions on the assembly and somehow ensures more accuracy on eyballing the shifter adjustment?
     
  8. Rifledriver

    Rifledriver Two Time F1 World Champ

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    That tool is not used for adjustment of the shift shaft, only for the forks and selectors.

    Fore and aft measurement is based on the shift rod position relative to the depth in the gate 2nd and 3rd gear. Rotational adjustment is determined by eye of the internal selector and its distancing from the R and 4th selectors while in 2nd gear.
     
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  9. Wade

    Wade Two Time F1 World Champ
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    I seem to recall that, when the seals fail, engine oil mixes with the trans oil, or vice versa. I wanted to clean and refresh both areas just to be sure.
     
  10. mike32

    mike32 Formula 3

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    Just remember if you drop the gearbox pan to look out for the springs and pins that drop out onto the floor, i changed the sump joint and found out the hard way.
    Removing the engine sump pan needs the dipstick tube removing or it will only come off half way- stories of not being able to get it out or cross threading trying to get it back in i understand. I got mine half down with the studs removed and managed to slip the new joint into place- and it did not leak thank god.
     
  11. moysiuan

    moysiuan Formula 3
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    Looks like I will end up with a spare fork and seletor adjuster tool...Thank you for the detailed explanation.
     
  12. moysiuan

    moysiuan Formula 3
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    Are the springs what causes the detent feel of the shifter? Never clear to me what these spings and balls are doing, I am not aware of any other car that has these things that fall out when removing a transaxle sump.

    Looks like due to the dip stick issue, this pan removal is best avoided if not essential. Other than changing the gasket for leaks, looks like it would not be necessary for typical service procedures.
     
  13. Rifledriver

    Rifledriver Two Time F1 World Champ

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    Some people just like to take off all the parts in front of them. I see it all the time. Then there are the people who take the advice here from the well meaning but inexperienced advisors.

    Drain all the oils.
     
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  14. Rifledriver

    Rifledriver Two Time F1 World Champ

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    All transmissions have some type of detent. It prevents the shifting mechanism from going into neutral when there is no load on the transmission.

    Removal of anything is best avoided if not required. Far more things get F'd up by taking them apart and putting them back together that just leaving them alone.
     
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  15. yelcab

    yelcab F1 Veteran
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    Amen. Guilty as charged when I am not thinking straight.
     
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  16. mike32

    mike32 Formula 3

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    I had a long face when i took the Gear Box cover off and saw the springs lying under the car- had to ring the dealers for advice. U R right about getting it wrong
     
  17. Rifledriver

    Rifledriver Two Time F1 World Champ

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    It happened to everyone of us once.
     
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  18. moysiuan

    moysiuan Formula 3
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    Got it, thanks.
     
  19. conan

    conan Formula Junior

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    When I decided to take off the oil pan for fixing the shaft seal, it was more about curiosity and checking for oil leaks. I am sure the inner seal can be changed with the oil pan on, but there is a risk that the seal drops inside if pushed to far in. Since I didn't try this, I would have kept the shaft just behind the casting of the oil sump to make a stop when trying to seat the seal between the washer and the casting.

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    In the photo you can see the washer first, then the seal and finally the casting behind. From the gearbox side you would have to squeeze the seal through the casting hole and seat it.
     
  20. Texas Forever

    Texas Forever Four Time F1 World Champ
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    You guys are scaring me.
     
  21. Wade

    Wade Two Time F1 World Champ
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    It's only difficult if you need to keep the car in service. If that's the concern, then it'll cost ya (but not too much) to have an experienced person complete the job instead. :)
     
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  22. moysiuan

    moysiuan Formula 3
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    That is very helpful thank you.
     
  23. conan

    conan Formula Junior

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    My findings related to the shaft springs and balls is that the gearbox feels sloppy and restrictive. Each of the three shafts for the gear pairs 1/RM etc, have three slots which align the forks to enable a smooth shifting in right-left direction as well as help keeping the gears in position.

    Without the alignment tool, chances are that the forks may not line up if you are adjusting the forks or when adjusting the shift shaft. The tool is not that difficult to make, but I anyhow made it hard for me.

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    The deep hole in the gearbox pan I thought I could make out of a piece of metal pipe, but it could have been easier done using a thicker alu block ...
     
  24. moysiuan

    moysiuan Formula 3
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  25. moysiuan

    moysiuan Formula 3
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    Interesting, the Verril Unobtanium tool I purchased would service this purpose, and it sounds like shift shaft adjustment would indeed benefit from the ball and springs being in place while adjusting. So looks like I may benefit from the tool which otherwise does not seem to be the common practice for helping with the shift shaft adjustment.
     

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