Old school transmission woes

[Rhymingmechanic]

Originally Posted by 4WD
I yield the balance of my time to Clinebarger


And if you decide on a rebuild, can you pull the trans yourself and drive it to the Dallas area?

 

[JLTD]

Originally Posted by 007
Gonna stick with the 400. I have had the 700R4 swap done before for the overdrive in a different car. Overall I like what I have with the exception of the issue and want to keep the car numbers matching. I have been getting quotes at around $1500 for a rebuild with premium parts including a new torque converter.


Not a bad price nowadays IMO.

 

[1978elcamino]

If you're not capable of doing the work that is understandable. However, that 1500 quote for a rebuild is probably soft parts and fluid (250 bucks tops) and the rest is labor. If you can R & R it yourself you can buy some really good 400's and a TCI converter online at a very reasonable price.

 

[clinebarger]

Originally Posted by 007
I had the filter, fluid and pan (ribbed with drain) changed a year ago and no issues until recently. Fluid is not burnt and trans shifts fine.


Change the filter & the O-ring on the filter extension.

Besides the first couple years of production.....The TH400 filter is designed to sit on the bottom of the pan, The Intake is actually on the top of the filter. Aftermarket pans cause all kinds of issues by letting the filter move around.

 

[wag123]

Originally Posted by wag123
If it were my car I would change the fluid and filter, put Max Life ATF and Lubegard Red in it, replace the vacuum modulator (because of the other problem), and drive it for a while. What is the worst thing that can happen? You end-up having to rebuild it anyway. But maybe, just maybe, that will take care of the problem. I am a big believer in LubeGard Red. It is one of the few additives that is actually good and actually works, it is definitely NOT snake oil!
If you are worried about metal shavings getting in the ATF, install a Magnefine filter (the real deal, not a knock-off) in the transmission cooler line.

Originally Posted by Fsharp
Whine like that could be from a little air getting into the pump, I'd try changing the fluid and filter first and when you do make sure the new filter seal seats properly there's not an old seal still jammed up in the hole or anything.

Originally Posted by clinebarger
Originally Posted by 007
I had the filter, fluid and pan (ribbed with drain) changed a year ago and no issues until recently. Fluid is not burnt and trans shifts fine.


Change the filter & the O-ring on the filter extension.

Besides the first couple years of production.....The TH400 filter is designed to sit on the bottom of the pan, The Intake is actually on the top of the filter. Aftermarket pans cause all kinds of issues by letting the filter move around.

There ya' go 007!

 

[4WD]

I have always stuck with stock pans … have added drain plugs, coolers, and external filters … but kept stock pan.

Now instead of having more ATF at the same temperature … it's easy to change fluid periodically and gets cooled and filtered (at 20 microns) fluid with OEM design around suction (and a better, cheaper, easy to change filter)

 

[ron350]

007 do some research and see if you need a deep pan filter conversion kit.

GM used a deep pan that took a longer pick up tube and a longer bolt. If I remember correctly I would use 2 o-rings where the tube goes into the case to prevent air leaking in.

 

[007]

Originally Posted by ron350
007 do some research and see if you need a deep pan filter conversion kit.

GM used a deep pan that took a longer pick up tube and a longer bolt. If I remember correctly I would use 2 o-rings where the tube goes into the case to prevent air leaking in.


Will do. I guess since everything was ok for the last year I am a little confused as to why now there is a problem. I thought everything was installed and working correctly.

 

[ron350]

Yes the problem may be in the pump but it is easier and cheaper to drop the pan than to drop the trans.

 

[The_Eric]

Originally Posted by 007
Originally Posted by ron350
007 do some research and see if you need a deep pan filter conversion kit.
GM used a deep pan that took a longer pick up tube and a longer bolt. If I remember correctly I would use 2 o-rings where the tube goes into the case to prevent air leaking in.


Will do. I guess since everything was ok for the last year I am a little confused as to why now there is a problem. I thought everything was installed and working correctly.

Clinebarger already answered that. The o-ring may only be a year old but could be a cheap Chinese piece of garbage or the filter potentially moving could have unseated it or the filter could have fallen completely out.


I would recommend that you pull the pan and inspect the o-ring and double check the filter's distance from the bottom of the pan

 

[007]

I did not install the new deep pan, change the filter or add the fluid. It was all done while the car was in the shop last year for other things and I was told the OEM pan was bent and leaking. Hence the replacement. Knowing the shop I would hope they used the correct filter. I will be dropping the pan and see if there are any issues before going the rebuild route. Pulled my back and for the last few weeks I have been unable to lay flat under the car! Thanks for all the insight!

 

[007]

Mechanic who changed the pan, fluid and filter last year gave me an offer. If I supply the new filter and fluid he will drop the pan with me check for metal shavings and if it looks ok we will install a new filter and fluid BEFORE I rebuild the tranny if necessary. Sounds like a plan!