There's been a couple of threads about replacing the valve guide seals on 24V motors (3.0 SOHC). Having now completed the repair, I can answer some of my earlier questions and hopefully provide some insight to those contemplating the same task
1) Do the seals wear on 24V motors? Did the seals need changing? Yes and Yes. I'd failed NJ state inspection for "visible smoke" (invisible stuff is OK I guess..). Early today, post repair it sailed through.
2)Overall degree of difficulty? About a 7/10, where 1=no brainer, and 10=buy new vehicle. Replacement of the seals took me about 6 days in total. Even with the correct valve spring compressor, there's a lot of time spent repositioning the Schley tool to get good leverage on the springs.It also takes some practice to hold the spring compressed and work the keepers in/out. In fact, I jury rigged wooden blocks and/or tie downs several times to "hold" the spring to avoid the situation of applying force with one hand and working dextrously with the other. Overall, I probably managed 1 seal/hr and I don't think it got much quicker with experience.
3) "Do the math" : This job requires repeating the basic procedure 24 times. Thats 48 keepers with a 100% success rate - a somewhat daunting process if you've never tackled a single one. One slip of the spring compressor and they are launched. Next time, I'd buy a spare set of keepers just for peace of mind.
4) "Sticky" retainers are an issue. Several times I went to compress the spring and the valve popped open. Once opened, it became much more difficult to maintain ~100psi in the cylinder. I put this down to carbon build up in the cylinder being blown onto the valve seat and a stone cold motor. Adding oil, keeping the valve open to "blow" out debris helped, but I still replaced 1 set of inlet seals with only 60psi and my 4cfm compressor running continuously. My eventual best solution was to whack the retainer with a large socket/mallet before attempting to compress the spring. A dull "thud" and no "hiss" means the spring has compressed.
5)The fore-aft coolant pipe seriously complicates the RHS inlet replacement. I might be very tempted to drain and remove if I had to repeat this task.
6) Don't be tempted by the "on-car" OHV screw-type spring compressors. They are too large and the 3.0 springs are progressive, making the windings too close to enable the "feet" to slot-in. Neither my "Stinger" or Sears unit worked with even with the springs the bench.
7) Be wary of any residual seal material. Several times I caught the remains of the inner lock ridge/ring left on the guide after I pulled the old seal. They don't always come quietly...
Lastly, a big thanks to those who have posted on this issue here and elsewhere. Shared information helped on several occasions, not least to provide a sanity check that the whole procedure would indeed cure the Monty's smoking habit. Hopefully the above will in turn help others contemplating the repair.
Paul
