Timing Probe Fitment Problem

[adamsanders]

I just bought a DTI Tech Time 3300-s timing meter off eBay a couple weeks ago. I’ve read plenty of threads on this site and others saying that the probe has to be filed to fit or the bracket hole has to be opened up slightly. I went ahead and filed the probe slightly and it fits good in the hole now. However, I can only insert it without the radial spring. If I put the spring on, it WILL NOT go in the hole past the spring. I have tried everything I know of. Anybody have any other ideas? I have used a 5/16” bit by hand and even double checked with a mirror - the hole is clean.

 

[gandalf]

I just looked at my unit, also a 3300-s, and am uncertain about your "radial spring". I have nothing which meets that description, and nothing which attaches to the inserted probe. Could you please post a picture of this spring?

BTW, my 3300-s works quite well with nothing attached to the probe insert.

 

[adamsanders]

I may have used the wrong terminology, it’s this piece that puts tension in the port to keep the probe from sliding around inadvertently.

 

[hacked89]

Yep I use it with no radial spring probe ground down a bit and harmonic balancer port drilled out slightly

 

[hacked89]

When you grind the probe you usually end up taking away the ridges that hold the spring

 

[adamsanders]

How do you keep the probe from sliding further down the port as the engine is running? Mine is snug but not that snug I don’t think

 

[gandalf]

I see the difference now. My probe has the detent to hold the radial spring, but my unit was not supplied with such a spring. I did not file down the size of the probe, though I did ream the hole it fits in, hand twisting a drill bit, size long forgotten. Mine is a snug fit, to the point I don't worry about the probe moving while the engine runs.

 

[Brian VT]

I messed with both "drilling" out the bracket (that didn't seem to accomplish much) and sanding down the probe. I sanded above and below the springs and finally got a good fit and have used it successfully about 15? times since then and I think? I've got my timing in a good spot. And I can get the probe in and out without too much trouble.
Even then it's still finicky about how far to seat it. Some say 2 +/- index cards? I messed with that and found if I just jam it down all the way it ended up working better than trying to find the right spacing. YMMV. Or you can buy the timing light.

 

[adamsanders]

So I’m assuming you haven’t had any problems with the balancer ruining the end of the probe with it shoved all the way down?

 

[sieg01]

The bracket hole on my engine was rusty.
We used a drill and removed the rust. Took some time.
Then the sensor fitted in - w/o any further modification.

Your thread reminds me, to open the bracket again and to fill it with grease.

 

[adamsanders]

Did you drill it out still on the truck? If so what was your setup? My alternator bracket looks like it would make it impossible to get in there with even a right angle drill.

 

[hacked89]

Did you drill it out still on the truck? If so what was your setup? My alternator bracket looks like it would make it impossible to get in there with even a right angle drill.

My one engine I drilled it out off the truck, in order to keep the cage spring at that time. Then an engine already in the truck there was no way I was fitting the drill so I removed the cage spring and ground it down further on the probe. Then just cleaned the port on the harmonic balancer with a drill bit. If you look on YouTube timing a 7.3 idi with a tech time 3300 I made a video of the whole process that you can scroll around and see the parts your looking for.

 

[adamsanders]

Okay I will take a look at that. What’s your YouTube channel name? So without the spring were you at all concerned with the probe working its way down the tube while the truck was running? Hitting the balancer essentially

 

[hacked89]

Okay I will take a look at that. What’s your YouTube channel name? So without the spring were you at all concerned with the probe working its way down the tube while the truck was running? Hitting the balancer essentially

The line is stiff enough that I just place the probe and take the slack out of it

 

[Brian VT]

So I’m assuming you haven’t had any problems with the balancer ruining the end of the probe with it shoved all the way down?

Looks and seems fine. I didn't know what else to do so I tried it. I figured it wouldn't take much off, if any. It doesn't look like it took anything off it.
I kept the spring things so I guess it stays just flush.
You should probably start with a business card or 2 and see if you get a reading.
If not, try what I did.