| Author |
Message |
Steve Magnusson (91tr)
| | Posted on Thursday, January 24, 2002 - 9:06 am: | |
The cam plug modification affects more models than just the 308GT4. It's shown in Technical Information No. 321 dated "6-12-77" (which I think is 06 Dec 1977 rather than 12 June 1977) and list the modification as "starting from the following engine numbers":
512BB - No. 00144
308GT4 - No. 02599
USA GTB - No. 00848
208GT4 - No. 00748 |
Don Hewey (1975gt4don)
| | Posted on Thursday, January 24, 2002 - 12:43 am: | |
Jeff, wow! Thanks for the info as I did not know that until you said something. I took that image from an 88 308GTS/B parts manual to show that the plug is in fact there, but in my 75 GT4 parts book, the plug is not there. Bobileff Motor Car has had my 2 camshafts for two days now and he still is not done. He said tomorrow. I am sure that he has other work ahead of mine, so that is probably the delay, but he mentioned, it is not an easy job. |
Jeff 77 GTB (Jbk)
| | Posted on Wednesday, January 23, 2002 - 7:52 pm: | |
Don,a correction: at least the early 77 GTBs did not have the seal plugs. With a flashlight I can see past the pin and can easily push a wire past it thru the interior of the camshaft. I don't know when they made the change, maybe mine has some older cams made before the upgrade. Makes it important to change the oring whenever the distributor is removed to keep it fresh and undamaged. |
Don Hewey (1975gt4don)
| | Posted on Wednesday, January 23, 2002 - 6:35 pm: | |
Mitchell, I hope this picture will illustrate what I am trying to say here. I labeled the part number that you need to get on the picture. Again here, the part number is: 112547
It is a freeze plug that is small. About half the diameter of a U.S. penny.
http://www.1john57.com/distributor.jpg |
Mitchell Minh Le (Yelcab1)
| | Posted on Wednesday, January 23, 2002 - 5:35 pm: | |
Don
Can you provide some more pictures, or point to a site where I can get some information? If it takes a propane torch, so be it, it shall be done. |
Don Hewey (1975gt4don)
| | Posted on Wednesday, January 23, 2002 - 4:49 pm: | |
Mitchell, very very important to note this. The 1975 GT4's are the only 308's that did not plug the intake cam where the spline for the distributor shaft goes into. In other words, the area where the shaft from the distributor enters, immediately after the shaft ends, there should be a plug, looking like a sort of freeze plug to seal off the inside of the cam, while simulataneously allowing the cam journal bearing hole in the camshaft itself to still be operative. I am having this modification done as I type this. The splined part of the intake cams (both intake cams need this mod). 76 on up 308's already have this retrofitted from the factory. The O-ring on the distributor shaft is a joke and will only hold up for 100 miles or so even with silicone sealant as an insurance against oil blowby. True, you may still have bad distributor shaft seals that are easy to replace, but the majority of your problem is the intake cam design flaw. Have a mechanic seal your intakes for you. I say this because the splined part is heat shrunk onto the intake cam and is also held in by a pin. the pin cannot be press fit out unless heated first by a propane torch. Alot of headache. GT carparts sells this freezeplug for $20 EACH. Highway robbery, I know. The other way is to have the mechanic seal off the intake cam by entering in through the opposite end of the intake cam. I have heard that this is easier to do rather than to take the splined part off.
Also, if your timing belt pulleys are leaking, replace them! You can start an oil fire by leaking oil. Remember that your front head is situated right over your front header that is immediately below. Those can get quite toasty no less. Pull the cams off and replace the cam seals. You dont have to pull the pulleys off except for your rear bank exhaust camshaft because this has the smog pulley attached. The smog pulley side seal is also very expensive---$35 or so. |
Jeff 77 GTB (Jbk)
| | Posted on Wednesday, January 23, 2002 - 11:21 am: | |
Distributor seals and gaskets can be changed. Cam seals behind the pulleys cannot. |
Mitchell Minh Le (Yelcab1)
| | Posted on Wednesday, January 23, 2002 - 9:05 am: | |
I want to do a valve check/adjustment on my GT4. I notice that the distributor seals and gaskets are leaking. Also the camshaft seals at the timing belt pulley are all leaking. THe Previous Owner had the timing belts a few months ago and I am not inclined to repeat that. My question is what else can I do while I have the covers off to do a valve adjustment and not remove the timing belts. Can I change the cam shaft seals at the pulley (Probably not), what about the distributor side?
Thanks,
Mitchell |
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