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Message |
    
Steven Strickland
New member
Username: steven_s
Post Number: 1
Registered: 05-2009
| | Posted on Thursday, May 21, 2009 - 01:30 pm: | 
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I HAVE A 1990 SUPRA WITH A PCM 351 & A 1.23 –1 PCM Transmission.
I just change the Transmission fluid and was out on the lake checking the level . The level looked good but after running it . I noticed that the housing was extremmly hot . I check the level again and it all seamed fine . The fluid that came out was very clean no burnt smell and we replaced exactly what we took out. My question is how hot do the transmitions get. I did not have a thermostat with me but I was not able to keep my hand on it for more than a couple of seconds. Any help or suggestions would be appreciated.
Transmission |
Steven Strickland
New member
Username: steven_s
Post Number: 2
Registered: 05-2009
| | Posted on Thursday, May 21, 2009 - 10:32 pm: |
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I would like to add to this post that. I drained all the fluid back out tonight to see if it looked burnt. I blew out the oil cooler and got about 2 quarts out of her. I can spin the transmission by hand it has a rough spot in it that will vibrate. I started the boat out of the water after I replaced all the flood and bumped the transmission it was a very loud vibrating sound in forward and reveres. I'm going to run out to the lake to check it tomorrow. I was wondering if the prop needed a load on it or if the fluid need to work its way back up in the transmission. |
oldmako
Advanced Member
Username: oldmako
Post Number: 116
Registered: 09-2004
| | Posted on Wednesday, May 27, 2009 - 01:37 pm: |
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The noise you heard while OUT of the water was most likely just the prop shaft spinning in a dry cutlass bearing. Not a good idea as it will quickly overheat.
Of course, it could be in trans itself as well. If you must run it in gear on the trailer, shoot the cutlass bearing with some aerosol lube first and limit your time in gear to the least amount possible. That bearing can be a pain to replace. |
makomark
Advanced Member
Username: makomark
Post Number: 539
Registered: 09-2008
| | Posted on Wednesday, May 27, 2009 - 05:11 pm: |
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The transmission fluid should not exceed 190-200 degrees (F) and the case temp usually doesn't exceed the fluid temp until shut-down. Those IR temp guns are perfect for that type of measurement. |
Steven Strickland
New member
Username: steven_s
Post Number: 3
Registered: 05-2009
| | Posted on Wednesday, May 27, 2009 - 05:43 pm: |
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Thank you all for all the comments. I took it out over the holiday weekend and was able to check the temp. It’s running close to 185 . I think that’s fine. I have a little bit of a clatter noise that comes and goes in it when idling around, but it goes away when I give it a little gas. I also feel a little vibration when I’m turning at a normal running speed. This has me confused. I'm beginning to think maybe the alignment has worked its way out or the cutlass bearing needs to be replaced, but it sure sound like it's in the transmission any thoughts would be appreciated. Also seams to have a bit of a winning noise that becomes louder with higher rpm’s. It ran well over the weekend burned through 25 gallons cursing the local lake. But something seams a little off and I would like to catch it before it becomes bigger problem. |
oldmako
Advanced Member
Username: oldmako
Post Number: 118
Registered: 09-2004
| | Posted on Wednesday, May 27, 2009 - 08:52 pm: |
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The clatter is most likely the damper plate between the flywheel and the trans. It absorbs the load and over time the springs will rust and weaken. They will then make noise at low throttle settings. Mine has done this for a LONG time. Should you replace it??? Probably, but there are many people running their boats in this same condition without a problem.
The vibration is most likely the prop itself. Pull it and take it to a reputable prop shop. For around a hundred bucks, they will true it and hopefully your problem will disappear.
To check the cutlass, just grab the shaft on either side of the strut and check for "looseness". If you search this site, you can find a more specific technique. But basically, it should be snug. |
makomark
Advanced Member
Username: makomark
Post Number: 543
Registered: 09-2008
| | Posted on Wednesday, May 27, 2009 - 11:20 pm: |
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Ditto the damper plate. If the rattle is gone by 1000 rpm, that's pretty common.
I'd suggest getting the prop run thru the propscan process. MUCH more accurate than the old pitch block approach. The results I had were worth every dollar spent.
The shake test for the cutlass is adequate, some mfg's get you a figure but its really hard to measure.
If the prop has hit something large, you should also do a quick check on the shaft. Usually, if it spins a full circle with the same resistance, that's good for the first check. The other thing is to put a board up to it and spin again using the board to check for trueness. |
