Planer Maintenance Question - Dewalt 734

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Forum topic by wonderand posted 07-27-2015 01:54 AM 1099 views 0 times favorited 6 replies Add to Favorites Watch
View wonderand's profile


9 posts in 1378 days

07-27-2015 01:54 AM

Topic tags/keywords: dewalt planer 734 gearbox grease lubrication question

Hi folks,

I’ve been reading LJ for a while, and really appreciate all of the advice you guys dole out on a regular basis. It’s been incredibly helpful as I get my small shop set up so thanks all. I looked through the threads but I didn’t see an answer to this question so I’m hoping someone can give me some advice.

The short version:

Can anyone recommend a grease to go in the gearbox? Dewalt used Shell Alvania EP 2 (since discontinued). Shell’s got a replacement (Gadus s2 v220) but it’s pretty expensive. Do you think I need an NLGI #1 or would white lithium suffice?

The long version:

I recently picked up a Dewalt 734 Planer on Craigslist for $50. That’s only a half brag and you’ll see why in a minute. The seller said that the cutterhead was binding on the posts and he couldn’t raise it or lower it. He didn’t want to take time to pull it apart and find out the problem so he put it up on CL for a cheap price. I checked it out, the motor sounded great with no issues and the feed rollers looked like they were in great shape. The side covers had been removed, but that didn’t bother me. The whole thing was filthy and there was some surface rust on the posts but nothing too bad. I ran it home as fast as possible. Thanks to previous posts, I knew it was likely rust binding to the carriage assembly so I broke everything down and started the long process of getting it cleaned up. I was able to knock the posts free with a deadblow mallet and a piece of hardwood and I used a scotch brite and wd40 to clean up the rust. I figured I’d give the whole machine a thorough going over since I already had it broken down. That’s when I noticed the switch cover was melted. It was subtle enough that I didn’t notice it when I was looking over the machine, but it clearly had been exposed to some high temps. When I looked under the carriage, the cutterhead and knives were totally covered with black soot. The motor seemed fine except for the labels on top, which after closer look had clearly warped from heat. The handle that raises and lowers the cutterhead had some subtle warping too. I’m guessing the seller removed the side covers because they were melted as well. After cleanup and rust removal the whole thing looks great, and I think it should be fine. The one thing that concerns me is when I opened up the gearbox, the grease inside was pretty stiff and the gears looked like they’d been blackened from heat. Here’s where we get to my questions:

Is it possible that the fire started in the gearbox? If so, how do I avoid that in the future? I cleaned out all of the grease inside. The gears turn freely and the bearings seem totally fine. However I do need to replace the grease. Does anyone know what grease I can use in there? Grainger has Mobilgrease CM-L that looks like it’ll work if I need an NLGI #1. Otherwise I have some white lithium grease on hand that I could use.

Lastly, are there any other safety checks I should be doing? There are no obvious signs of fire near the switch or the motor assembly, just the gearbox and outside. The gearbox was pretty packed full of grease and I’ve heard that fluid friction could cause it to heat up significantly but I don’t know if that could be the cause.

Thanks to anyone who chose to read that diatribe. I’m happy to send any pictures if needed.

6 replies so far

View jonah's profile


1721 posts in 3321 days

#1 posted 07-27-2015 02:40 AM

More power to you if you want to fix the thing, but I honestly wouldn’t trust that it wouldn’t burst into flames the second I turned it on. If forced to use it, I would only do so outdoors, where I couldn’t burn my house down.

Did you know about the burning before you bought it, or just the rusty posts? If not, I’d feel pretty well fleeced by the seller.

View Pezking7p's profile


3217 posts in 1674 days

#2 posted 07-27-2015 02:48 AM

Is it possible that it got overloaded and stopped feeding the wood, causing the blades to overheat the wood and start a fire?

-- -Dan

View wonderand's profile


9 posts in 1378 days

#3 posted 07-27-2015 06:42 AM

Thanks for the replies.

Jonah, yeah I didn’t know about the fire before buying it. I was annoyed that he hid that, but more annoyed with myself that I didn’t heed the red flag of the low price and spend more time going over it. I’ve reached out to the seller basically saying that I accept that I bought it as-is and just want info on what happened, but I haven’t heard anything and I doubt I will. In the end, I can probably make my money back selling it for parts, but if I can get it (safely) working I’d prefer that.

Dan, that’s a definite possibility. The highest concentration of soot was on the cutterhead.

I’ve run the motor a few times under no load without any issues. Once I figure out the grease question and get it reassembled I’ll be testing it very thoroughly outside.

View wonderand's profile


9 posts in 1378 days

#4 posted 07-27-2015 06:02 PM

UPDATE: I got a response from the seller and he let me know that the planer was next to a dust collector that caught fire a few years back. He said that he used it for about a year after that before putting it in storage (which is when the posts rusted). The cord, switch, and electrical components are all free from signs of damage so I believe that’s what happened. I’ll still exercise caution when I get it back up and running.

View Eric's profile


83 posts in 2998 days

#5 posted 11-07-2015 08:49 PM

Hi guys, I also have this planer and I really enjoy it a lot. However, when I was planing some boards recently, I noticed some squeaking that started to occur and I’m not sure what it’s from. I was wondering if anybody that owns one here would know? It doesn’t squeak the whole time, just when I feed a board through it. And when the squeaking does occur, it only happens once every second while the board is passing through.

I did wax the bottom of the planer, but the problem still exists. I haven’t had any trouble with the board not pulling through, so I’m a little worried that one of the barrings are wearing out. On the other hand, I haven’t cleaned the feed rollers though. Has anyone had a problem with the planer squeaking?

-- Eric

View tomsteve's profile


790 posts in 1242 days

#6 posted 11-07-2015 11:27 PM

eric,instead of asking the same question in 6 different threads it would probably be more effective to start one thread of your own.

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