: Timing Chain, Oil Pan, 1970 Deville 472 ????

03-09-13, 05:38 AM
Hello all,

I am trying to give my 70 DV Convo a better life and have made some good progress. (in another thread if interested)

BUT i have googled and googled and googled again about the whole do you HAVE to remove the oil pan according to the factory manual to replace the timing chain.

I've read so many conflicting stories\article my head is spinning.

Here's my story and concerns and hopefully there will be one place to see the many opinions and hopefully the answer I'm looking for.

I bought the new timing set last year and had it down to the harmonic balancer but was not prepared to tackle that so I let her be. I had a 73 CDV when I was younger and a backyard mechanic replaced the chain in my front yard. I do not recall the oil pan needing to come out but I could be wrong.

Fast forward to today. I have almost everything out of the way including the radiator so I can get the impact wrench in there to pull the balancer. Everything is fine....I'm following my FSM step by step and then I get to the step where it says remove oil pan as described in sec x.

I'm thinking "no problem" remove a few screws drop that pan out of the way......nothing but room on this car.

1. it wants me to disconnect the Y pipe. It has probably never been removed or at best 25 yrs ago. Sounds like $350 for a new exhaust to me. Maybe I'm wrong I've never removed a y pipe before but in my experience getting old exhaust pipes off and back on never seemed possible.

2. Remove starter. Ok no biggie.

3. Remove drag link and pitman arm and such. Ok not fun but can be done.

4. Front tranny cover. again no biggie

Here is where I'd like to get some info.

Can I leave the pan on and easily remove the front cover and reinstall? If the reason is a proper seal at bottom of front cover I'm confident in my making excessively large silicone goop gaskets. Or is it that the front cover will be difficult or impossible to reinstall corectly with the oil pan on.

Can I skip the Y pipe and remove the rest and wiggle her out?

Has anyone done it without removing the pan or the y pipe?

I was spinning the balancer and watching the distributor. There was almost no play. I'm just not sure if it has ever been replaced. I'd hate to be so close to the damn thing twice and not replace it then the inevitable happens.

Can't wait to hear your thoughts or experiences.

03-17-13, 08:28 AM
For some reason, that sounds like way more work than should be necessary to do a timing chain. Most of the time, this job is not that involved. It sounds like a nightmare reading the manual.

Having had bad experiences, I would definitely replace it, but I'm kinda thinking that the manual may be overkill or excessively cautious.

03-17-13, 07:22 PM
Thanks DR,

Yeah I was thinking that it would be a fairly simple job. The whole oil pan thing is killing me. There is definitely no way I can get it out without removing all that stuff.

If I don't drop the pan I can't seem to get the bottom gasket of the front cover seated properly.

My mechanic is gonna swing by this week and take a look. Hoping we can just drop the pan a few inches and re seal.

03-19-13, 12:36 AM
If you can drop the pan a little your golden. Some try to seal it with silicone or whatever, I don't recommend that. Just for thought if you get a new exhaust get rid of the y-pipe. Go straight pipe all the way back. Not unless you want it original. Wish I logged in sooner.

03-19-13, 01:47 AM
Thanks Caddygas,

I can definitely get that pan down a little. I was just worried once I pry it away from the engine that I couldn't seal it up properly. I was always taught if you remove anything with a gasket the seal must be cleaned and re sealed. I will not have the room to clean out the old gasket and put in a new one.

The y pipe and intermediate pipe are either original or were installed 20+ years ago. They are rusty but solid so I assume the latter. I was able to weld in new stuff muffler back with no issues. For budget reasons hoping to keep it that way for a while. Not terribly concerned about keeping her 100% original. Just operational and not a mangled gerryrigged mess some of my old cars,became.

I haven't done the work yet but planning on a few hours weds-fri this week.

From the input here and from others here's the plan. Drop the pan as much as I can in the front. That will allow me to seat the bottom gasket on the front cover properly and reassemble. Run her and check for leaks. Hope it will be ok. I really wanted to clean out that pan though. I'm sure 40 yrs of fun are at the bottom. But I can use that $$$ other places at this time.

If she leaks ill figure my options from there.

03-19-13, 03:06 AM
Yes, you are right about moving and installing gaskets. That is a chance because there might be a rip in the gasket, etc. Hope yours is ok, strong chance of getting it re sealed. I know what you mean by cleaning the pan, how it look inside, any shavings on the magnet? Is there one? etc.

03-20-13, 09:30 AM
Hi all, I'm new to this forum, and so far I've found the questions n answers very interesting. I currently own 2 Caddys, 70 cdv 472 eng. & 92 Brghm 5.7 eng. I look forward to exchanging tips with other caddy owners. I've owned a total of 24 cars since 1977, 19 were caddys! I love these cars. If I may offer


Hi all, I'm new to this forum, and so far I've found the questions n answers very interesting. I currently own 2 Caddys, 70 cdv 472 eng. & 92 Brghm 5.7 eng. I look forward to exchanging tips with other caddy owners. I've owned a total of 24 cars since 1977, 19 were caddys! I love these cars. Smelvis,If I may offer you a suggestion, if u have the space and somethin else to drive, from my experience, you probably do better removing engine from car. On an engine stand u can examine everything. To people can have it out in about 3 hrs or less if you hustle. The advantage of a caddy of this age is that its not comp controled, thus fewer sensors to locate. Just make sure tag connectors and vac hoses for easier re-assembly

03-21-13, 01:36 AM
Thanks Musiman. I probably should have at this point but I'm moving forward with the timing change. In fact tonight I pulled it all apart.

I'm going to take the chance on not dropping the pan, or not completely anyway. After taking a good look I'm confident that not only can I do this but also this engine has been gone through or ver well cared for. There is no evidence of the old nylon gears (meaning im pretty sure that someone changed it) and it looks very clean inside.

As they say I probably should have let sleeping dogs lie but I plan on putting daisy to work this summer. I'll have the piece of mind that the timing chain is solid.

Here's a few pics with the cover off. I'll take a few as I go and report back. I know I'm not out of the woods yet and if I have to completely drop the pan I may just pull the engine.


03-21-13, 03:24 AM
Because are pans and covers are designed that way along with other engines, oh the fun. Coming this far, yeah why not all gaskets? As you said coming this far just a little more love won't hurt.

03-30-13, 10:44 PM
It looks like the chain and gears have been changed before.

04-01-13, 08:04 PM
Yes it had definitely been replaced before which was nice to see. I didn't see any evidence of plastic bits anywhere.

When the re installed the gears they did not line up the dowel hole on the camshaft sprocket the when the marks are line up the engine is in the #1 firing position not #4

I installed the same way. She's back together and fired right up. About a week now a few cruises and no leaks. I used a little super black silicone along the bottom lip of the front cover where it meets the oil pan. It fit together nicely and I left it alone for a few days prior to starting to let it cure.

Verdict: it can be done without removing the oil pan. However if I had found some plastic bit I probably would have dropped the pan to clean everything out but everything looked nice and clean.

Ps I added the install pics.

04-02-13, 12:57 AM
Happy to hear you got her done. Glad you let the silicone cure first, that's why I really don't recommend it some people don't do it right.

Did the book say #4 or do I not understand? Maybe a typo.

04-03-13, 07:09 PM
Thanks CG,

Yes the book said the timing marks lined up would put the engine in #4 firing position and to rotate 180• to get #1 firing position. Not wanting to move anything I just followed my predecessors lead and installed sprocket without the holes lined up on the camshaft.