I have replaced the front seal on my 700r-4 twice in the last 2 weeks,it blows them out,a friend says its the front bushing and pump,i dont know what to do,any suggestions?,is it worth having the front seal,bushing,and pump replaced at a trans shop for $400?,the trans has a shift kit in it so i am thinking this could be some of the cause of the pressure building up and blowing out the seal,but transfixleo your the expert and i trust your advice.

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www.rearman.com/camarokid.htm

If it aint a V-8 that $hit aint fast!,unless its a GN,lol!

305 tpi,700r-4 with shift kit,16 by 9 American Racing cross laced wheels,My mods are minimal,just a bunch of little $hit.Anyone know where to get underdrive pulleys for a v-belt set up?

[This message has been edited by IROC KID (edited June 13, 2001).]

 

'86 700 right? That is your problem! Here is the deal. GM in the never ending brilliance has a hard time understanding that if more oil is getting past the pump bushing than the drain hole can handle, it will build up pressure and blow it out!

To fix this simply requires opening up the drain passage to a minimum of 1/4" from the bushing area all the way to through the stator half (three passages that connect). It is not hard to do but the tranny must be out and the pump should be apart. I would say this is common knowledge in the indusrty but maybe your guy didn't know this. You should also make sure that there is a tight fit on the pump bushing and the dowel holes are not oblonge.

 

Is this something i could do myself?,me and my brother have been doing it,we can pull it and install it in a night,but i am oblivious as to what i should do to fix it,do i have to pull the trans apart at all?,i want to save money here,what should i replace and how should i make the drain passage bigger?

 

Yes but I would take my time on this. Get a manual so when all of the vanes fall out and the little orange spring and... Well you get the idea. Have a torque wrench set for 20 ft/lbs ready too.

Here is another great idea as long as you are there. Install a TransGo Hi Rev pump kit. It is just a set of high tensile strength rings and a HD priming spring. Costs maybe $15 but it saves wiping out a pump (common) and it keeps shifts from getting soft when hot at high RPM's.

 

I am taking it to my dads friend who does tranny work,he said to bring it down so he could tear it apart and look at it,do you have any suggestions or recommendations so i can tell the guy this or see if he is on the same page as you with what i should do with the trans,i dont want him to just replace the seal,bushing,and pump when there are other things he should also do while he is at it,i appreciate your input,i will be bringing the trans to him tommorow because i am pulling it out tonight.

 

I'm not transfixleo, but... i've been following the post. Pics are attached.

there's a passage right behind the front seal http://www.angelfire.com/pa4/camaro350/frontsealbore that should be 'carefully' opened up to 5/16". I say carefully because if you ram the drill bit down too far after connecting the passage, you may break through another passage in the pump. Even if this occurs, I was told not to worry about it as it won't 'change' anything, but doing it right sounds better.

Also clean the seal bore very well and use red loctite or my favorite the green loctite 'press fit assist' or reataining compound http://www.angelfire.com/pa4/camaro350/locfrontseal http://www.angelfire.com/pa4/camaro350/loctite either will work good if the surfaces are clean. Most seals have a red soft 'coating' on the bore surface. Lightly sand this off as it prevents the loctite from really 'lockin'

As for doing a pump re-build, make sure the ring surfaces are not scored or looking like a record. If it is, you really should get a different pump housing. Otherwise there's a small grove around the back side of the slide that accepts an o-ring http://www.angelfire.com/pa4/camaro350/botpumpring , then is covered by a steel one. It's hard to hold it together when setting it down in there but a little vaseline down in the groove works wonders...sounds a little sick

Those two little seals on the slide http://www.angelfire.com/pa4/camaro350/twoseals
http://www.angelfire.com/pa4/camaro350/slideseal (the round and the rectangular) could be a PIA to get in there, even with the slide all the way back. Use a double slide spring http://www.angelfire.com/pa4/camaro350/twosprings
http://www.angelfire.com/pa4/camaro350/twosprings
as this provides better more controlled pressure. Also inspect your front bushing and slam in a new one if its shot http://www.angelfire.com/pa4/camaro350/frontbushing as this will build up pressure.

Also check the two teflon seals <A HREF="http://www.angelfire.com/pa4/camaro350/twoseals" TARGET=_blank>
and make sure they are in good condition. Theres little o-rings around the pump bolt heads that you could reuse, but make sure to inspect them. As for what comes out of the case by removing them here's a pic
http://www.angelfire.com/pa4/camaro350/pump

If your input shaft has the split teflon seals you should upgrade to the solids, but there's more work involved here. There's a special install/sizing tool, but you could use cut plastic drinking cups to stretch the seals down over the splines [URL=http://www.angelfire.com/pa4/camaro350/teflonring]http://www.angelfire.com/pa4/camaro350/teflonring</A> and then use the cut cups on the outside with a heaterhose clamp tightened to size them make sure to do from the bottom up (there's 3) You could also remove some of the endplay while in there by changing out the selective washer sitting on top of where the input shaft joins the aluminum, but this involves pulling the band/drum which involves pulling the valvebody so this might not be a quick deal. If your stocker is stamped with a '68' you could put a '72' in if you go this far. http://www.angelfire.com/pa4/camaro350/selectivewash Just make sure you still have some endplay on the shaft after re-assembly.

I know this sounds like alot, but you might as well while your there. By the way the 13 vane rotor kit Ihttp://www.angelfire.com/pa4/camaro350/pumpvane got with the double slide springs and all the seals/rings to so the pump I got from http://www.hptransparts.com for less than $35. I doubt if they would break the washer kits and seal kits down as they are together, but they are still faily cheap and you could use them in a future rebuild which might be a good time since you went this far into the case to change the 3-4 clutches as these usually wear severe compared to the others which probably look new.

Also most later pumps have a front seal retainer that slides over the front snout and grabs the pump housing and presses the seal in. I doubt it is more effective than loctite, but it is made by alto and I don't know the p#..

I prolly scared the hell outa ya, but the most work involved is pulling the trans/reinstalling so if you're there...

But really, loctite that seal and drill it out and the pump kit is a good idea at the least.

Good luck with your ventures!



[This message has been edited by JoelOl75 (edited June 15, 2001).]

 

Thanks Joel075,me and my brother pulled the trans in about an hour and a half and its going to the trans guy tommorow,i will ask him what he plans to do in detail and if he says the same stuff as you and transfixleo then i will be relieved but if he is a jerkoff then i will have to either find someone else or make the suggestions to him, i definately want him to drill that drain passage like you guys suggested and replace the pump and bushing,and anything else that is worn or broken.

 

I wouldn't neccesarily replace the pump unless it is worn. Also, on the 13 vane pump the passages are not the same for that one so I really wouldn't recommend doing that. You can upgrade to the 10 Vane with no problem although if you have proper clearances on the 7 vane you will never know the difference and it has more pump volume than a 13!

 

There is an easier way, remove the seal, clean new seal and trans with brake cleaner and install a new seal with red loctite, then install a GM front seal retainer. It would be easier quicker and alot cheaper. I'm only saying because my '90 700 is homebuilt, shifts great and hasn't blown a seal yet, I didn't know to enlarge the drain hole until after I built it so it's stock size. It'll probably blow out tomorrow now that I've said this. )

 

The '90 is drilled ALMOST all of the way. They somehow missed the matching hole in the stator half but they made a lot of changes since '82. They moved the hole, enlarged the hole, reinforced the area of the bushing and put a lip in to keep the bushing from moving forward. They also use a metal clip to retain the seal. I like to Lock-Tite the seal too.

 

Thanks guys for all the info,the guy put in a retaining clip and used locktite too,i got a 30 day warrantee on the repair work,so if she last 30 days then she should be ok for awhile,before it would last a week if i was lucky.

------------------
www.rearman.com/camarokid.htm
www.iroc-zpost.com
If it aint a V-8 that $hit aint fast!,unless its a GN,lol!

305 tpi,700r-4 with shift kit,16 by 9 American Racing cross laced wheels,My mods are minimal,just a bunch of little $hit.Anyone know where to get underdrive pulleys for a v-belt set up?
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