home register FAQ memberlist calendar

Go Back   Turbobricks Forums > Mechanical > maintenance & nonperformance

Reply
 
Thread Tools Display Modes
Old 07-09-2020, 09:07 AM   #1
G-Tech 940
Board Member
 
G-Tech 940's Avatar
 
Join Date: Feb 2020
Location: Ontario, Canada
Default Zinc Chromate on alternator housing

I have the opportunity to get some things zinc plated for free. Either in zinc chromate (silver) or zinc dichromate (gold).

Would be using a plating process like this.

I've got a bunch of old Bosch alternators, I was thinking of taking a few apart and sending in the aluminum shells to be plated.

I'm just not sure if having the alternator shell plated will be "safe" for the car, in that I don't want to find out the coating causes some crazy static buildup and cause damage to the ECU or start a fire or something else. I'm probably worried over nothing, but I would rather ask the stupid question than make the stupid mistake!

Would anyone know;

a) would chromate plating an alternator shell cause any issue?
b) is there any sort of power surge protection for the ECU? (I would assume there is, but again, don't want to make a dumb, expensive mistake) I don't mind breaking an alternator, but I'd rather not break my car testing it out.

I am also going to get the hard coolant pipe plated, it's the one that runs under the exhaust manifold around the back of the engine on B230FT. I have a new one from STS that is bare stainless. Little bit concerned about the heat in the area it's mounted though. The plating can take about 460-490 F for an hour or two (to the best of my research) before 'dulling' the finish. There will be 220(?) F coolant running through the pipe though, so I'm thinking that it might keep it cool enough.
G-Tech 940 is offline   Reply With Quote
Old 07-09-2020, 09:34 AM   #2
apachechef
Burnt Sierra Madre
 
Join Date: Jan 2009
Location: Fort Joe Smith, Klendathu
Default

You want to plate stainless?


Do you want to stitch your waistband to your belly in case your belt and suspenders both fail?

And why not a Denso 100a instead of a Bosch?
__________________
Quote:
Originally Posted by lummert View Post
Dammit, Lummert.
Quote:
Originally Posted by Jesse8931 View Post
Well keep us updated on how your dumbass plan goes.
apachechef is offline   Reply With Quote
Old 07-09-2020, 09:38 AM   #3
nel621
Board Member
 
Join Date: Apr 2009
Default

Not sure about Zinc but I'm sure you have seen many show cars with fully chrome plated engines. I don't think there will be a problem. Also I have a friend that had his alternator chrome plated on his 240, no issues. Good luck. Wish I had access to free plating. I would do most of the bolts in yellow, the washer bottle holder in white, all of the hose clamps, etc.
nel621 is offline   Reply With Quote
Old 07-09-2020, 09:52 AM   #4
G-Tech 940
Board Member
 
G-Tech 940's Avatar
 
Join Date: Feb 2020
Location: Ontario, Canada
Default

Quote:
Originally Posted by apachechef View Post
You want to plate stainless?...........And why not a Denso 100a instead of a Bosch?
I have a Bosch 100a on the car and 3-4 on the shelf (I think a couple are missing voltage regulators, but I have a bag of spares). I've also got some 80a and 70a alts that I would like to sell, and if I can plate the shells for free, then maybe I can get a few more bucks for them. I would love a Denso but it is not in the budget right now, especially when I have free options. If this does work though, I would like to do it with a Denso someday.

My first choice was to powdercoat both the alternator shells and the coolant pipe, but I found out yesterday that my budget has been effectively paused for the foreseeable future. Any car money is going to have to come from selling whatever parts I have, and even then, that money might not go back into the car. The pipe is stainless, yeah maybe I should just leave it, you're right. I was just thinking of zinc as a replacement for the powdercoating, but yeah, leaving it as stainless would be better. Thanks!

Quote:
Originally Posted by nel621 View Post
Not sure about Zinc but I'm sure you have seen many show cars with fully chrome plated engines. I don't think there will be a problem. Also I have a friend that had his alternator chrome plated on his 240, no issues. Good luck. Wish I had access to free plating. I would do most of the bolts in yellow, the washer bottle holder in white, all of the hose clamps, etc.
Appreciate your insight, thanks!
G-Tech 940 is offline   Reply With Quote
Old 07-09-2020, 11:36 AM   #5
142 guy
Board Member
 
Join Date: May 2014
Location: Saskatchewan, Canada
Default

Zinc chromate is nominally an electrical conductor; however, depending on the plating process used (cyanide versus acid baths) the end product may or may not be conducting. A non conducting coating on the alternator would certainly mess up the ground current flow through the alternator frame; but, so would powder coating. Of course, you could always grind off the coating on the alternator mounting bolt to make sure you have a good electrical connection.
142 guy is offline   Reply With Quote
Old 07-09-2020, 03:28 PM   #6
dl242gt
Happy playing the blues
 
dl242gt's Avatar
 
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
Default

The bosch alternator housing grounds through the long case stud. As long as the bolt is clean and the threads are clean in the housing. It will conduct just fine. The alternator will function and look good.

I would polish the coolant return pipe and then it's done.
dl242gt is offline   Reply With Quote
Old 08-02-2020, 02:38 PM   #7
940TOwner
Newbie
 
940TOwner's Avatar
 
Join Date: Aug 2020
Default

In need of a bracket to hold alternator in place (to engine) Any for sale ?
Old part # 3514231. New part # 6842481
940TOwner is offline   Reply With Quote
Old 08-03-2020, 12:56 AM   #8
c1800
Board Member
 
Join Date: Jun 2014
Location: Alberta
Default

Quote:
Originally Posted by 940TOwner View Post
In need of a bracket to hold alternator in place (to engine) Any for sale ?
Old part # 3514231. New part # 6842481
Suggest you post your request in the wanted section rather than a random thread that mentions alternator. And along with the part number, specify the engine it applies to.
c1800 is offline   Reply With Quote
Old 08-03-2020, 03:55 AM   #9
Otto Mattik
Chief Bottle Washer
 
Otto Mattik's Avatar
 
Join Date: Dec 2015
Location: Upper Midwest..more or less
Default

It would be interesting seeing the end results of your endeavors.

__________________
Desperate need of elf assistant for interior work - Cash/Beer option $


Feedback thread: http://forums.turbobricks.com/showthread.php?t=323689
Otto Mattik is offline   Reply With Quote
Old 08-06-2020, 09:59 PM   #10
G-Tech 940
Board Member
 
G-Tech 940's Avatar
 
Join Date: Feb 2020
Location: Ontario, Canada
Default

Quote:
Originally Posted by Otto Mattik View Post
It would be interesting seeing the end results of your endeavors.

I still haven't figured out how to take the alternator apart. I have removed every screw and bolt I can see apart from 4 phillips screws that were behind the pulley. They are stuck in there. I sprayed some PB but havent gone back to check yet.

The housing doesn't want to split I don't think. I looked at some videos but nothing was exactly the same.
G-Tech 940 is offline   Reply With Quote
Old 08-07-2020, 03:41 AM   #11
Otto Mattik
Chief Bottle Washer
 
Otto Mattik's Avatar
 
Join Date: Dec 2015
Location: Upper Midwest..more or less
Default

You can try an impact driver, the 4 screws closer together are the bearing plate screws.
Use a puller, to spilt the shells(if the shells won't come apart).

Here is a youtube link for an e30 Bosch alternator rebuild:



Last edited by Otto Mattik; 08-08-2020 at 03:32 AM..
Otto Mattik is offline   Reply With Quote
Old 08-07-2020, 07:47 PM   #12
dl242gt
Happy playing the blues
 
dl242gt's Avatar
 
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
Default

Those long screws on the outer rim of the case are the four long screws that hold it together. Once you remove those. You can separate the housing. Hope the video shows how to separate the stubborn ones.
dl242gt is offline   Reply With Quote
Old 08-08-2020, 03:32 AM   #13
Otto Mattik
Chief Bottle Washer
 
Otto Mattik's Avatar
 
Join Date: Dec 2015
Location: Upper Midwest..more or less
Default

Unfortunately the video jumps around with speeded up sequences. From his description it sounds like he removed everything except the bearing plate screws. A photo from G-tech would make this clear.

Otto Mattik is offline   Reply With Quote
Old 08-08-2020, 08:55 AM   #14
G-Tech 940
Board Member
 
G-Tech 940's Avatar
 
Join Date: Feb 2020
Location: Ontario, Canada
Default

Hey guys,

Here is what I have so far. It's a newer model Bosch 100A unit. Looks a bit different than the one in the video (although I have several of those so if this works out then the video will still be useful for when I do those ones)

I was not able to budge any of the bearing ring screws, and I have stripped at least one. I was able to get half of the shell off with a puller that I had on hand, luckily It was included with a bunch of old Volvo tools I picked up.




^sorry for it being a bit blurry^



G-Tech 940 is offline   Reply With Quote
Old 08-10-2020, 08:02 PM   #15
Otto Mattik
Chief Bottle Washer
 
Otto Mattik's Avatar
 
Join Date: Dec 2015
Location: Upper Midwest..more or less
Default

Quote:
Originally Posted by G-Tech 940 View Post
I was not able to budge any of the bearing ring screws, and I have stripped at least one.

Can you include a detailed image of the problem area ?

Otto Mattik is offline   Reply With Quote
Old 08-11-2020, 02:58 PM   #16
dl242gt
Happy playing the blues
 
dl242gt's Avatar
 
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
Default

I've only rebuilt the older Bosch style and Denso alternators. I had one of those that was good so I gave it to a friend to use. It was in such nice used shape and passed testing so I never took it apart. That type of Bosch alternator happened after Bosch bought Denso and those started appearing on the 93-95 940s we got. I don't know if Bosch still owns Denso but they did for awhile in the 90s.
dl242gt is offline   Reply With Quote
Old 08-11-2020, 03:20 PM   #17
G-Tech 940
Board Member
 
G-Tech 940's Avatar
 
Join Date: Feb 2020
Location: Ontario, Canada
Default





First two pics are of the bearing ring







the second set of pics is the back housing, that's what I need to get off to plate it. I don't have a big enough puller to get on the shaft and hooked on the housing too. Is a puller all it takes?
G-Tech 940 is offline   Reply With Quote
Old 08-11-2020, 03:21 PM   #18
G-Tech 940
Board Member
 
G-Tech 940's Avatar
 
Join Date: Feb 2020
Location: Ontario, Canada
Default

I just realized these pictures are ****, sorry!. Still, it's the rear housing that I don't know how to remove.
G-Tech 940 is offline   Reply With Quote
Old 08-11-2020, 06:08 PM   #19
dl242gt
Happy playing the blues
 
dl242gt's Avatar
 
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
Default

There is a small 6202 bearing on the rear housing. It's a press fit into the housing. As I recall I had to use my press on the end of the shaft to remove the rotor. It ruins the bearing when you do that. I had to use a dremel to cut the inner race off the shaft. Don't lose the spring washer under the bearing. If I recall correctly. The bearing numbers are 6202 for the small one and 6303 for the big bearing. 6202 is also the pilot bearing and the bosch alternators use one, too.
dl242gt is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 11:48 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.