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hey guys I have a 1988 c4 with a Doug Nash that I am currently rebuilding. Now I just used a plate to push down the piston and removed my double springs underneath the plate.I noticed some small cracks on about three spring holders. Is this something to be concerned about and maybe replace the piston? Cracked three spring holes Regular spring holes/ no cracks
I will admit the last time I had one of those in hand was the late 80s maybe even 90 I seem to recall they had some rough casting inside and some none vital areas.
Are sure it's cracks or just unfinished
I will admit the last time I had one of those in hand was the late 80s maybe even 90 I seem to recall they had some rough casting inside and some none vital areas.
Are sure it's cracks or just unfinished
Im not really a professional on this stuff but I was kinda able to feel some cracks i believe when I stuck my finger inside them. I’m not too sure what rough casting would truly look like or feel like. I just am really trying to make this overdrive the absolute best I can make it to prevent a failure for a while. I have two units on my table right now. A 1988(my car) and a 1985(“rebuilt”unit). The 85 had a blown piston and my 88 has the one with small cracks I just showed. I’m using mostly all 88 parts since everyone’s said they’re better but I want to make sure that this piston is safe and will last me another 100000. I currently have an extremely strong orbital gear and some other strong parts that I have snatched up from around the forums and from the old units. I also have a rebuild kit, new atf pump sprag,front case bearing and a good 88 thrust washer. I can buy a brand new forged piston I believe off someone if need be but if this piston is good and strong then I’d like to prevent more money spent.
I know the feeling your there do once do it right with no what ifs, if I can get ahold of a friend who taught me how to rebuild them see if he can recall the finish. He probably would walk to the garage to look. And no he doesn't give up parts
I know the feeling your there do once do it right with no what ifs, if I can get ahold of a friend who taught me how to rebuild them see if he can recall the finish. He probably would walk to the garage to look. And no he doesn't give up parts
Any help is amazing, dw about parts because I have a couple places I’ve been getting everything from. Like I said I believe I know someone who’s selling some forged ones. Let me know once you know anything. Thank you so much again!
He got back to me, if you could find a new one get it. It may be compromised and a spring could get loose and that would not be good.
As he reminded me surface easy parts you can roll the dice, but buried expensive parts that takes time take no risk
He got back to me, if you could find a new one get it. It may be compromised and a spring could get loose and that would not be good.
As he reminded me surface easy parts you can roll the dice, but buried expensive parts that takes time take no risk
thank you so much, I’ll look into buying a new one off the guy I was going to!
am pretty sure those are surface shrinkage cracks from the casting process. a forged piece will be stronger because the grain structures are aligned during the process, castings have random grain structures and are somewhat weaker. .02
hey guys I have a 1988 c4 with a Doug Nash that I am currently rebuilding. Now I just used a plate to push down the piston and removed my double springs underneath the plate.I noticed some small cracks on about three spring holders. Is this something to be concerned about and maybe replace the piston? Cracked three spring holes
Are you talking about in the holes? I've never rebuilt a Doug-Nash... but GM has a lot of castings that look like this, and what I'm seeing in the holes do not look like cracks, but are casting imperfections. IMHO
So is this just a casting problem? It’s a little rough to the touch I believe. It’s ran 88,000 miles so I don’t anticipate something like this being destroyed but would it be safe to run? I talked to Brian at SK Speed and they are selling the forged ones for around 220 which isn’t terrible. I checked all of my springs and I see no visible damage like connected springs or anything. Maybe a little bit of over heating on the outside of them. I’m just concerned for the future and my long term reliability.
So is this just a casting problem? It’s a little rough to the touch I believe. It’s ran 88,000 miles so I don’t anticipate something like this being destroyed but would it be safe to run? I talked to Brian at SK Speed and they are selling the forged ones for around 220 which isn’t terrible. I checked all of my springs and I see no visible damage like connected springs or anything. Maybe a little bit of over heating on the outside of them. I’m just concerned for the future and my long term reliability.
I'm not qualified to say whether you should go with something stronger... but this does not look like cracks to me, just casting flaws... which isn't a problem. I will say though, if I was rebuilding a transmission, and didn't want to do it again... I'd replace it with all the best parts, especially for items that are prone to breaking.
I'm not qualified to say whether you should go with something stronger... but this does not look like cracks to me, just casting flaws... which isn't a problem. I will say though, if I was rebuilding a transmission, and didn't want to do it again... I'd replace it with all the best parts, especially for items that are prone to breaking.
Yeah I agree, im going to buy the forged piston because I’ve seen a cracked piston in my 1985 and this one has some rough edges. I think it’ll be best if I upgrade and go stronger, especially with something brand new.
Doug Nash piston spring
. Like I said I believe I know someone who’s selling some forged ones. Let me know once you know anything. Thank you so much again!
